uart integrated into SOC

diff --git a/openlane/uart/base.sdc b/openlane/uart/base.sdc
new file mode 100644
index 0000000..1eab2c3
--- /dev/null
+++ b/openlane/uart/base.sdc

@@ -0,0 +1,34 @@
+set_units -time ns
+set ::env(CORE_CLOCK_PERIOD) "10"
+set ::env(CORE_CLOCK_PORT)   "app_clk"
+
+######################################
+# WB Clock domain input output
+######################################
+create_clock [get_ports $::env(CORE_CLOCK_PORT)]  -name $::env(CORE_CLOCK_PORT)  -period $::env(CORE_CLOCK_PERIOD)
+set core_input_delay_value [expr $::env(CORE_CLOCK_PERIOD) * 0.6]
+set core_output_delay_value [expr $::env(CORE_CLOCK_PERIOD) * 0.6]
+puts "\[INFO\]: Setting wb output delay to:$core_output_delay_value"
+puts "\[INFO\]: Setting wb input delay to: $core_input_delay_value"
+
+
+set_input_delay 2.0 -clock [get_clocks $::env(CORE_CLOCK_PORT)] {arst_n}
+
+set_input_delay  $core_input_delay_value   -clock [get_clocks $::env(CORE_CLOCK_PORT)] [get_port reg_cs*]
+set_input_delay  $core_input_delay_value   -clock [get_clocks $::env(CORE_CLOCK_PORT)] [get_port reg_addr*]
+set_input_delay  $core_input_delay_value   -clock [get_clocks $::env(CORE_CLOCK_PORT)] [get_port reg_wr*]
+set_input_delay  $core_input_delay_value   -clock [get_clocks $::env(CORE_CLOCK_PORT)] [get_port reg_be*]
+set_input_delay  $core_input_delay_value   -clock [get_clocks $::env(CORE_CLOCK_PORT)] [get_port reg_wdata*]
+
+
+set_output_delay $core_output_delay_value  -clock [get_clocks $::env(CORE_CLOCK_PORT)] [get_port reg_rdata*]
+set_output_delay $core_output_delay_value  -clock [get_clocks $::env(CORE_CLOCK_PORT)] [get_port reg_ack*]
+
+
+
+# TODO set this as parameter
+set_driving_cell -lib_cell $::env(SYNTH_DRIVING_CELL) -pin $::env(SYNTH_DRIVING_CELL_PIN) [all_inputs]
+set cap_load [expr $::env(SYNTH_CAP_LOAD) / 1000.0]
+puts "\[INFO\]: Setting load to: $cap_load"
+set_load  $cap_load [all_outputs]
+

diff --git a/openlane/uart/config.tcl b/openlane/uart/config.tcl
new file mode 100644
index 0000000..f0aea1f
--- /dev/null
+++ b/openlane/uart/config.tcl

@@ -0,0 +1,64 @@
+# Global
+# ------
+
+set script_dir [file dirname [file normalize [info script]]]
+# Name
+set ::env(DESIGN_NAME) uart_core
+
+
+
+# Timing configuration
+set ::env(CLOCK_PERIOD) "10"
+set ::env(CLOCK_PORT) "app_clk"
+
+
+# Sources
+# -------
+
+# Local sources + no2usb sources
+set ::env(VERILOG_FILES) "\
+    $script_dir/../../verilog/rtl/uart/src/uart_core.sv  \
+    $script_dir/../../verilog/rtl/uart/src/uart_cfg.sv   \
+    $script_dir/../../verilog/rtl/uart/src/uart_rxfsm.sv \
+    $script_dir/../../verilog/rtl/uart/src/uart_txfsm.sv \
+    $script_dir/../../verilog/rtl/lib/async_fifo_th.sv   \
+    $script_dir/../../verilog/rtl/lib/reset_sync.sv      \
+    "
+
+#set ::env(VERILOG_INCLUDE_DIRS) [glob $script_dir/../../verilog/rtl/sdram_ctrl/src/defs ]
+
+set ::env(SDC_FILE) "$script_dir/base.sdc"
+set ::env(BASE_SDC_FILE) "$script_dir/base.sdc"
+
+
+# Floorplanning
+# -------------
+
+set ::env(FP_PIN_ORDER_CFG) $::env(DESIGN_DIR)/pin_order.cfg
+set ::env(FP_SIZING) "absolute"
+set ::env(DIE_AREA) [list 0.0 0.0 100.0 100.0]
+
+
+
+
+set ::env(FP_PDN_VPITCH) 50
+set ::env(PDN_CFG) $script_dir/pdn.tcl
+
+set ::env(FP_VERTICAL_HALO) 6
+set ::env(PL_TARGET_DENSITY) 0.52
+set ::env(PL_TARGET_DENSITY_CELLS) 0.38
+set ::env(PL_OPENPHYSYN_OPTIMIZATIONS) 1
+set ::env(CELL_PAD) 4
+
+set ::env(GLB_RT_ADJUSTMENT) 0
+set ::env(GLB_RT_L2_ADJUSTMENT) 0.2
+set ::env(GLB_RT_L3_ADJUSTMENT) 0.25
+set ::env(GLB_RT_L4_ADJUSTMENT) 0.2
+set ::env(GLB_RT_L5_ADJUSTMENT) 0.1
+set ::env(GLB_RT_L6_ADJUSTMENT) 0.1
+set ::env(GLB_RT_TILES) 14
+set ::env(GLB_RT_MAXLAYER) 5
+
+set ::env(DIODE_INSERTION_STRATEGY) 4
+
+

diff --git a/openlane/uart/pdn.tcl b/openlane/uart/pdn.tcl
new file mode 100644
index 0000000..1fe689b
--- /dev/null
+++ b/openlane/uart/pdn.tcl

@@ -0,0 +1,49 @@
+# SPDX-FileCopyrightText: 2020 Efabless Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
+
+# Power nets
+set ::power_nets $::env(VDD_PIN)
+set ::ground_nets $::env(GND_PIN)
+
+set ::macro_blockage_layer_list "li1 met1 met2 met3 met4 met5"
+
+pdngen::specify_grid stdcell {
+    name grid
+    rails {
+	    met1 {width 0.48 pitch $::env(PLACE_SITE_HEIGHT) offset 0}
+    }
+    straps {
+	    met4 {width 1.6 pitch $::env(FP_PDN_VPITCH) offset $::env(FP_PDN_VOFFSET)}
+	    met5 {width 1.6 pitch $::env(FP_PDN_HPITCH) offset $::env(FP_PDN_HOFFSET)}
+    }
+    connect {{met1 met4} {met4 met5}}
+}
+
+pdngen::specify_grid macro {
+    power_pins "VPWR"
+    ground_pins "VGND"
+    blockages "li1 met1 met2 met3 met4"
+    straps { 
+    } 
+    connect {{met4_PIN_ver met5}}
+}
+
+set ::halo 5
+
+# POWER or GROUND #Std. cell rails starting with power or ground rails at the bottom of the core area
+set ::rails_start_with "POWER" ;
+
+# POWER or GROUND #Upper metal stripes starting with power or ground rails at the left/bottom of the core area
+set ::stripes_start_with "POWER" ;

diff --git a/openlane/uart/pin_order.cfg b/openlane/uart/pin_order.cfg
new file mode 100644
index 0000000..f7b568d
--- /dev/null
+++ b/openlane/uart/pin_order.cfg

@@ -0,0 +1,16 @@
+#BUS_SORT
+
+#N
+app_clk 
+arst_n 
+si
+so
+
+#S
+reg_cs 
+reg_wr 
+reg_addr.*
+reg_be
+reg_wdata.*
+reg_rdata.*
+reg_ack 

diff --git a/verilog/dv/agents/uart_agent.v b/verilog/dv/agents/uart_agent.v
new file mode 100644
index 0000000..4c9d05d
--- /dev/null
+++ b/verilog/dv/agents/uart_agent.v

@@ -0,0 +1,321 @@
+
+module uart_agent (
+	mclk,
+	txd,
+	rxd
+	);
+
+input	mclk;
+output	txd;
+
+input	rxd;
+
+event	uart_read_done, uart_write_done;
+event	error_detected,uart_parity_error, uart_stop_error1, uart_stop_error2;
+event 	uart_timeout_error;
+event	abort;
+
+reg [15:0] rx_count;
+reg [15:0] tx_count;
+reg [15:0] par_err_count;
+reg [15:0] stop_err1_cnt;
+reg [15:0] stop_err2_cnt;
+reg [15:0] timeout_err_cnt;
+reg [15:0] err_cnt;
+
+reg 	   txd, read, write;
+wire	   uart_rx_clk;
+reg	   uart_clk;
+reg	   stop_err_check;
+
+integer timeout_count;
+integer data_bit_number;
+reg [15:0] clk_count;
+
+reg      error_ind; // 1 indicate error
+
+initial 
+begin
+	txd = 1'b1;
+ 	uart_clk = 0;
+	clk_count = 0;
+	stop_err_check = 0;
+  error_ind = 0;
+end
+
+always @(posedge mclk)
+begin
+   if (clk_count == 'h0) begin
+      uart_clk = ~uart_clk;
+      clk_count = control_setup.divisor;	
+   end else begin
+      clk_count = clk_count - 1;	
+   end
+end
+assign uart_rx_clk = ~uart_clk;
+
+always @(posedge mclk)
+begin
+	timeout_count = timeout_count + 1;
+	if (timeout_count == (control_setup.maxtime * 16))
+		-> abort;
+end
+
+always @uart_read_done
+    rx_count = rx_count + 1;
+
+always @uart_write_done
+    tx_count = tx_count + 1;
+
+always @uart_parity_error begin
+    error_ind = 1;
+    par_err_count = par_err_count + 1;
+end
+
+always @uart_stop_error1 begin
+    error_ind = 1;
+    stop_err1_cnt = stop_err1_cnt + 1;
+end
+
+always @uart_stop_error2 begin
+    error_ind = 1;
+    stop_err2_cnt = stop_err2_cnt + 1;
+end
+
+always @uart_timeout_error begin
+    error_ind = 1;
+    timeout_err_cnt = timeout_err_cnt + 1;
+end
+
+
+always @error_detected begin
+    error_ind = 1;
+    err_cnt = err_cnt + 1;
+end
+
+
+////////////////////////////////////////////////////////////////////////////////
+task uart_init;
+begin
+  read = 0;
+  write = 0;
+  tx_count = 0;
+  rx_count = 0;
+  stop_err_check = 0;
+  par_err_count = 0;
+  stop_err1_cnt = 0;
+  stop_err2_cnt = 0;
+  timeout_err_cnt = 0;
+  err_cnt = 0;
+
+end 
+endtask 
+
+
+////////////////////////////////////////////////////////////////////////////////
+task read_char_chk;
+input 	expected_data;
+
+integer i;
+reg	[7:0] expected_data;
+reg 	[7:0] data;
+reg	parity;
+
+begin
+	data <= 8'h0;
+	parity <= 1;
+	timeout_count = 0;
+
+fork	
+   begin : loop_1
+        @(abort)
+         $display ("%m: >>>>> Exceed time limit, uart no responce.\n");
+         ->uart_timeout_error;
+         disable loop_2;
+   end
+
+   begin : loop_2
+
+// start cycle
+	@(negedge rxd) 
+	 disable loop_1;
+	 read <= 1;
+
+// data cycle
+	@(posedge uart_rx_clk);
+	 for (i = 0; i < data_bit_number; i = i + 1)
+	  begin
+	    @(posedge uart_rx_clk)
+	    data[i] <=  rxd;
+	    parity <= parity ^ rxd;
+	  end		
+
+// parity cycle
+	if(control_setup.parity_en)
+	begin
+          @(posedge uart_rx_clk);
+	  if ((control_setup.even_odd_parity && (rxd == parity)) ||
+	     (!control_setup.even_odd_parity && (rxd != parity)))
+	     begin
+		$display ("%m: >>>>>  Parity Error");	
+ 		-> error_detected;
+		-> uart_parity_error;
+	     end
+	end
+
+// stop cycle 1
+        @(posedge uart_rx_clk);	
+	  if (!rxd)
+	     begin
+		$display ("%m: >>>>>  Stop signal 1 Error");	
+ 		-> error_detected;
+		-> uart_stop_error1;
+	     end
+
+// stop cycle 2
+	if (control_setup.stop_bit_number)
+	begin
+	      @(posedge uart_rx_clk);	// stop cycle 2
+		if (!rxd)
+		  begin
+		    $display ("%m: >>>>>  Stop signal 2 Error");	
+ 		    -> error_detected;
+		    -> uart_stop_error2;
+		  end
+	end
+
+
+// wait another half cycle for tx_done signal
+		@(negedge uart_rx_clk);
+	read <= 0;
+	-> uart_read_done;
+
+	if (expected_data != data)
+	begin
+		$display ("%m: Error! Data return is %h, expecting %h", data, expected_data);
+		-> error_detected;
+	end
+	else
+		$display ("%m: Data match  %h", expected_data);
+
+	$display ("%m:... Read Data from UART done cnt :%d...",rx_count +1);
+   end
+join
+
+end
+
+endtask
+
+
+////////////////////////////////////////////////////////////////////////////////
+task write_char;
+input [7:0] data;
+
+integer i;
+reg parity;	// 0: odd parity, 1: even parity
+
+begin
+	parity <=  #1 1;
+
+// start cycle
+	@(posedge uart_clk)
+	 begin
+		txd <= #1 0;
+		write <= #1 1;
+	 end
+
+// data cycle
+	begin
+	   for (i = 0; i < data_bit_number; i = i + 1)
+	   begin
+		@(posedge uart_clk)
+		    txd <= #1 data[i];
+		parity <= parity ^ data[i];
+	   end
+	end
+
+// parity cycle
+	if (control_setup.parity_en)
+	begin
+		@(posedge uart_clk)
+			txd <= #1 
+//				control_setup.stick_parity ? ~control_setup.even_odd_parity : 
+				control_setup.even_odd_parity ? !parity : parity;
+	end
+
+// stop cycle 1
+	@(posedge uart_clk)
+		txd <= #1 stop_err_check ? 0 : 1;
+
+// stop cycle 2
+	@(posedge uart_clk);
+		txd <= #1 1;
+	if (data_bit_number == 5)
+		@(negedge uart_clk);
+	else if (control_setup.stop_bit_number)
+		@(posedge uart_clk);
+
+	write <= #1 0;
+	$display ("%m:... Write data %h to UART done cnt : %d ...\n", data,tx_count+1);
+	-> uart_write_done;
+end
+endtask
+
+
+////////////////////////////////////////////////////////////////////////////////
+task control_setup;
+input	  [1:0] data_bit_set;	
+input		stop_bit_number;
+input		parity_en;
+input		even_odd_parity;
+input		stick_parity;
+input	 [15:0] maxtime;
+input	 [15:0] divisor;
+
+begin
+        clk_count = divisor;	
+	data_bit_number = data_bit_set + 5;
+end
+endtask
+
+
+////////////////////////////////////////////////////////////////////////////////
+task report_status;
+output 	[15:0] rx_nu;
+output 	[15:0] tx_nu;
+begin
+	$display ("-------------------- UART Reporting Configuration --------------------");
+	$display ("	Data bit number setting is : %0d", data_bit_number);
+	$display ("	Stop bit number setting is : %0d", control_setup.stop_bit_number + 1);
+	$display ("	Divisor of Uart clock   is : %0d", control_setup.divisor);
+	if (control_setup.parity_en) 
+	$display ("	Parity is enable");
+	else
+	$display ("	Parity is disable");
+	
+	if (control_setup.even_odd_parity)
+	$display ("	Even parity setting");
+	else	
+	$display ("	Odd parity setting");
+
+
+	$display ("-----------------------------------------------------------------");
+
+	$display ("-------------------- Reporting Status --------------------\n");
+	$display ("	Number of character received is : %d", rx_count);
+	$display ("	Number of character sent     is : %d", tx_count);
+	$display ("	Number of parity error rxd   is : %d", par_err_count);
+	$display ("	Number of stop1  error rxd   is : %d", stop_err1_cnt);
+	$display ("	Number of stop2  error rxd   is : %d", stop_err2_cnt);
+	$display ("	Number of timeout error      is : %d", timeout_err_cnt);
+	$display ("	Number of error              is : %d", err_cnt);
+	$display ("-----------------------------------------------------------------");
+
+	rx_nu = rx_count;
+	tx_nu = tx_count;
+end
+endtask
+
+
+////////////////////////////////////////////////////////////////////////////////
+endmodule

diff --git a/verilog/dv/user_uart/.user_uart.c.un~ b/verilog/dv/user_uart/.user_uart.c.un~
new file mode 100644
index 0000000..5835313
--- /dev/null
+++ b/verilog/dv/user_uart/.user_uart.c.un~
Binary files differ

diff --git a/verilog/dv/user_uart/Makefile b/verilog/dv/user_uart/Makefile
new file mode 100644
index 0000000..1ec201f
--- /dev/null
+++ b/verilog/dv/user_uart/Makefile

@@ -0,0 +1,83 @@
+# SPDX-FileCopyrightText: 2020 Efabless Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+## Caravel Pointers
+CARAVEL_ROOT ?= ../../../caravel
+CARAVEL_PATH ?= $(CARAVEL_ROOT)
+CARAVEL_FIRMWARE_PATH = $(CARAVEL_PATH)/verilog/dv/caravel
+CARAVEL_VERILOG_PATH  = $(CARAVEL_PATH)/verilog
+CARAVEL_RTL_PATH = $(CARAVEL_VERILOG_PATH)/rtl
+CARAVEL_BEHAVIOURAL_MODELS = $(CARAVEL_VERILOG_PATH)/dv/caravel
+
+## User Project Pointers
+UPRJ_VERILOG_PATH ?= ../../../verilog
+UPRJ_RTL_PATH = $(UPRJ_VERILOG_PATH)/rtl
+UPRJ_BEHAVIOURAL_MODELS = ../model
+UPRJ_INCLUDE_PATH1 = $(UPRJ_RTL_PATH)/syntacore/scr1/src/includes
+UPRJ_INCLUDE_PATH2 = $(UPRJ_RTL_PATH)/sdram_ctrl/src/defs
+
+## RISCV GCC 
+GCC_PATH?=/ef/apps/bin
+GCC_PREFIX?=riscv64-unknown-elf
+PDK_PATH?=/ef/tech/SW/sky130A
+
+## Simulation mode: RTL/GL
+SIM?=RTL
+
+.SUFFIXES:
+
+PATTERN = user_uart
+
+all:  ${PATTERN:=.vcd}
+
+hex:  ${PATTERN:=.hex}
+
+vvp:  ${PATTERN:=.vvp}
+
+%.vvp: %_tb.v %.hex
+ifeq ($(SIM),RTL)
+	iverilog -g2005-sv -DFUNCTIONAL -DSIM -I $(PDK_PATH) \
+	-I $(CARAVEL_BEHAVIOURAL_MODELS) -I $(CARAVEL_RTL_PATH) \
+	-I $(UPRJ_BEHAVIOURAL_MODELS)    -I $(UPRJ_RTL_PATH) \
+	-I $(UPRJ_INCLUDE_PATH1)    -I $(UPRJ_INCLUDE_PATH2) \
+	$< -o $@ 
+else  
+	iverilog -DFUNCTIONAL -DSIM -DGL -I $(PDK_PATH) \
+	-I $(CARAVEL_BEHAVIOURAL_MODELS) -I $(CARAVEL_RTL_PATH) -I $(CARAVEL_VERILOG_PATH) \
+	-I $(UPRJ_BEHAVIOURAL_MODELS) -I$(UPRJ_RTL_PATH)   -I $(UPRJ_VERILOG_PATH) \
+	$< -o $@ 
+endif
+
+%.vcd: %.vvp
+	vvp $<
+
+%.elf: %.c $(CARAVEL_FIRMWARE_PATH)/sections.lds $(CARAVEL_FIRMWARE_PATH)/start.s
+	${GCC_PREFIX}-gcc -I $(CARAVEL_PATH) -march=rv32imc -mabi=ilp32 -Wl,-Bstatic,-T,$(CARAVEL_FIRMWARE_PATH)/sections.lds,--strip-debug -ffreestanding -nostdlib -o $@ $(CARAVEL_FIRMWARE_PATH)/start.s $<
+
+%.hex: %.elf
+	${GCC_PREFIX}-objcopy -O verilog $< $@ 
+	# to fix flash base address
+	sed -i 's/@10000000/@00000000/g' $@
+
+%.bin: %.elf
+	${GCC_PREFIX}-objcopy -O binary $< /dev/stdout | tail -c +1048577 > $@
+
+# ---- Clean ----
+
+clean:
+	rm -f *.elf *.hex *.bin *.vvp *.vcd *.log
+
+.PHONY: clean hex all

diff --git a/verilog/dv/user_uart/run_iverilog b/verilog/dv/user_uart/run_iverilog
new file mode 100644
index 0000000..6f95c23
--- /dev/null
+++ b/verilog/dv/user_uart/run_iverilog

@@ -0,0 +1,20 @@
+riscv64-unknown-elf-gcc -O2 -funroll-loops -fpeel-loops -fgcse-sm -fgcse-las  -D__RVC_EXT -static -std=gnu99 -fno-common -fno-builtin-printf -DTCM=1 -Wa,-march=rv32imc -march=rv32imc -mabi=ilp32 -DFLAGS_STR=\""-O2 -funroll-loops -fpeel-loops -fgcse-sm -fgcse-las "\"  -c -I./ -I../../rtl/syntacore/scr1/sim/tests/common  user_uart.c -o user_uart.o
+
+riscv64-unknown-elf-gcc -O2 -funroll-loops -fpeel-loops -fgcse-sm -fgcse-las  -D__RVC_EXT -static -std=gnu99 -fno-common -fno-builtin-printf -DTCM=1 -Wa,-march=rv32imc -march=rv32imc -mabi=ilp32 -DFLAGS_STR=\""-O2 -funroll-loops -fpeel-loops -fgcse-sm -fgcse-las "\"  -D__ASSEMBLY__=1 -c -I./ -I../../rtl/syntacore/scr1/sim/tests/common/  ../../rtl/syntacore/scr1/sim/tests/common/crt_tcm.S -o crt_tcm.o
+
+riscv64-unknown-elf-gcc -o user_uart.elf -T ../../rtl/syntacore/scr1/sim/tests/common/link_tcm.ld user_uart.o crt_tcm.o -nostartfiles -nostdlib -lc -lgcc -march=rv32imc -mabi=ilp32
+
+riscv64-unknown-elf-objcopy -O verilog user_uart.elf user_uart.hex
+
+riscv64-unknown-elf-objdump -D user_uart.elf > user_uart.dump
+
+rm crt_tcm.o user_uart.o
+
+#iverilog with waveform dump
+#iverilog -g2005-sv -DWFDUMP -I $PDK_PATH -I ../ -I ../../../verilog/rtl -I ../../../verilog/rtl/syntacore/scr1/src/includes   -I ../../../verilog/rtl/sdram_ctrl/src/defs -I $$CARAVEL_ROOT/verilog/dv/caravel -I ../model ../agents user_uart_tb.v -o user_uart_tb.vvp
+
+iverilog -g2005-sv -I $PDK_PATH -I ../ -I ../../../verilog/rtl -I ../../../verilog/rtl/syntacore/scr1/src/includes   -I ../../../verilog/rtl/sdram_ctrl/src/defs -I $CARAVEL_ROOT/verilog/dv/caravel -I ../model -I ../agents user_uart_tb.v -o user_uart_tb.vvp
+
+vvp user_uart_tb.vvp | tee test.log
+
+\rm -rf user_uart_tb.vvp

diff --git a/verilog/dv/user_uart/uprj_netlists.v b/verilog/dv/user_uart/uprj_netlists.v
new file mode 100644
index 0000000..0aa46db
--- /dev/null
+++ b/verilog/dv/user_uart/uprj_netlists.v

@@ -0,0 +1,82 @@
+// SPDX-FileCopyrightText: 2020 Efabless Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
+
+// Include caravel global defines for the number of the user project IO pads 
+`define USE_POWER_PINS
+
+     `include "spi_master/src/spim_top.sv"
+     `include "spi_master/src/spim_regs.sv"
+     `include "spi_master/src/spim_clkgen.sv"
+     `include "spi_master/src/spim_ctrl.sv"
+     `include "spi_master/src/spim_rx.sv"
+     `include "spi_master/src/spim_tx.sv"
+
+     `include "uart/src/uart_core.sv"
+     `include "uart/src/uart_cfg.sv"
+     `include "uart/src/uart_rxfsm.sv"
+     `include "uart/src/uart_txfsm.sv"
+     `include "lib/async_fifo_th.sv"  
+     `include "lib/reset_sync.sv"  
+
+     `include "sdram_ctrl/src/top/sdrc_top.v" 
+     `include "sdram_ctrl/src/wb2sdrc/wb2sdrc.v" 
+     `include "lib/async_fifo.sv"  
+     `include "sdram_ctrl/src/core/sdrc_core.v"
+     `include "sdram_ctrl/src/core/sdrc_bank_ctl.v"
+     `include "sdram_ctrl/src/core/sdrc_bank_fsm.v"
+     `include "sdram_ctrl/src/core/sdrc_bs_convert.v"
+     `include "sdram_ctrl/src/core/sdrc_req_gen.v"
+     `include "sdram_ctrl/src/core/sdrc_xfr_ctl.v"
+
+     `include "lib/registers.v"
+     `include "lib/clk_ctl.v"
+     `include "digital_core/src/glbl_cfg.sv"
+     `include "digital_core/src/digital_core.sv"
+
+     `include "lib/wb_stagging.sv"
+     `include "wb_interconnect/src/wb_arb.sv"
+     `include "wb_interconnect/src/wb_interconnect.sv"
+
+
+     `include "syntacore/scr1/src/core/pipeline/scr1_pipe_hdu.sv"
+     `include "syntacore/scr1/src/core/pipeline/scr1_pipe_tdu.sv"
+     `include "syntacore/scr1/src/core/pipeline/scr1_ipic.sv"
+     `include "syntacore/scr1/src/core/pipeline/scr1_pipe_csr.sv"
+     `include "syntacore/scr1/src/core/pipeline/scr1_pipe_exu.sv"
+     `include "syntacore/scr1/src/core/pipeline/scr1_pipe_ialu.sv"
+     `include "syntacore/scr1/src/core/pipeline/scr1_pipe_idu.sv"
+     `include "syntacore/scr1/src/core/pipeline/scr1_pipe_ifu.sv"
+     `include "syntacore/scr1/src/core/pipeline/scr1_pipe_lsu.sv"
+     `include "syntacore/scr1/src/core/pipeline/scr1_pipe_mprf.sv"
+     `include "syntacore/scr1/src/core/pipeline/scr1_pipe_top.sv"
+     `include "syntacore/scr1/src/core/primitives/scr1_reset_cells.sv"
+     `include "syntacore/scr1/src/core/primitives/scr1_cg.sv"
+     `include "syntacore/scr1/src/core/scr1_clk_ctrl.sv"
+     `include "syntacore/scr1/src/core/scr1_tapc_shift_reg.sv"
+     `include "syntacore/scr1/src/core/scr1_tapc.sv"
+     `include "syntacore/scr1/src/core/scr1_tapc_synchronizer.sv"
+     `include "syntacore/scr1/src/core/scr1_core_top.sv"
+     `include "syntacore/scr1/src/core/scr1_dm.sv"
+     `include "syntacore/scr1/src/core/scr1_dmi.sv"
+     `include "syntacore/scr1/src/core/scr1_scu.sv"
+      
+     `include "syntacore/scr1/src/top/scr1_dmem_router.sv"
+     `include "syntacore/scr1/src/top/scr1_dp_memory.sv"
+     `include "syntacore/scr1/src/top/scr1_tcm.sv"
+     `include "syntacore/scr1/src/top/scr1_timer.sv"
+     `include "syntacore/scr1/src/top/scr1_dmem_wb.sv"
+     `include "syntacore/scr1/src/top/scr1_imem_wb.sv"
+     `include "syntacore/scr1/src/top/scr1_top_wb.sv"
+     `include "lib/sync_fifo.sv"

diff --git a/verilog/dv/user_uart/user_uart.c b/verilog/dv/user_uart/user_uart.c
new file mode 100644
index 0000000..cb8c107
--- /dev/null
+++ b/verilog/dv/user_uart/user_uart.c

@@ -0,0 +1,43 @@
+
+#define SC_SIM_OUTPORT (0xf0000000)
+#define uint32_t  long
+
+#define reg_mprj_globl_reg0  (*(volatile uint32_t*)0x30000000)
+#define reg_mprj_globl_reg1  (*(volatile uint32_t*)0x30000004)
+#define reg_mprj_globl_reg2  (*(volatile uint32_t*)0x30000008)
+#define reg_mprj_globl_reg3  (*(volatile uint32_t*)0x3000000C)
+#define reg_mprj_globl_reg4  (*(volatile uint32_t*)0x30000010)
+#define reg_mprj_globl_reg5  (*(volatile uint32_t*)0x30000014)
+#define reg_mprj_globl_reg6  (*(volatile uint32_t*)0x30000018)
+#define reg_mprj_globl_reg7  (*(volatile uint32_t*)0x3000001C)
+#define reg_mprj_globl_reg8  (*(volatile uint32_t*)0x30000020)
+#define reg_mprj_globl_reg9  (*(volatile uint32_t*)0x30000024)
+#define reg_mprj_globl_reg10 (*(volatile uint32_t*)0x30000028)
+#define reg_mprj_globl_reg11 (*(volatile uint32_t*)0x3000002C)
+#define reg_mprj_globl_reg12 (*(volatile uint32_t*)0x30000030)
+#define reg_mprj_globl_reg13 (*(volatile uint32_t*)0x30000034)
+#define reg_mprj_globl_reg14 (*(volatile uint32_t*)0x30000038)
+#define reg_mprj_globl_reg15 (*(volatile uint32_t*)0x3000003C)
+
+#define reg_mprj_uart_reg0 (*(volatile uint32_t*)0x30010000)
+#define reg_mprj_uart_reg1 (*(volatile uint32_t*)0x30010004)
+#define reg_mprj_uart_reg2 (*(volatile uint32_t*)0x30010008)
+#define reg_mprj_uart_reg3 (*(volatile uint32_t*)0x3001000C)
+#define reg_mprj_uart_reg4 (*(volatile uint32_t*)0x30010010)
+#define reg_mprj_uart_reg5 (*(volatile uint32_t*)0x30010014)
+#define reg_mprj_uart_reg6 (*(volatile uint32_t*)0x30010018)
+#define reg_mprj_uart_reg7 (*(volatile uint32_t*)0x3001001C)
+#define reg_mprj_uart_reg8 (*(volatile uint32_t*)0x30010020)
+
+int main()
+{
+
+    while(1) {
+       // Check UART RX fifo has data, if available loop back the data
+       if(reg_mprj_uart_reg8 != 0) { 
+	   reg_mprj_uart_reg5 = reg_mprj_uart_reg6;
+       }
+    }
+
+    return 0;
+}

diff --git a/verilog/dv/user_uart/user_uart_tb.v b/verilog/dv/user_uart/user_uart_tb.v
new file mode 100644
index 0000000..84938f5
--- /dev/null
+++ b/verilog/dv/user_uart/user_uart_tb.v

@@ -0,0 +1,423 @@
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+////  Standalone User validation Test bench                       ////
+////                                                              ////
+////  This file is part of the YIFive cores project               ////
+////  http://www.opencores.org/cores/yifive/                      ////
+////                                                              ////
+////  Description                                                 ////
+////   This is a standalone test bench to validate the            ////
+////   Digital core.                                              ////
+////   1. User Risc core is booted using  compiled code of        ////
+////      user_risc_boot.c                                        ////
+////   2. User Risc core uses Serial Flash and SDRAM to boot      ////
+////   3. After successful boot, Risc core will check the UART    ////
+////      RX Data, If it's available then it loop back the same   ////
+////      data in uart tx                                         ////
+////   4. Test bench send random 40 character towards User uart   ////
+////      and expect same data to return back                     ////
+////                                                              ////
+////  To Do:                                                      ////
+////    nothing                                                   ////
+////                                                              ////
+////  Author(s):                                                  ////
+////      - Dinesh Annayya, dinesha@opencores.org                 ////
+////                                                              ////
+////  Revision :                                                  ////
+////    0.1 - 16th Feb 2021, Dinesh A                             ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+//// Copyright (C) 2000 Authors and OPENCORES.ORG                 ////
+////                                                              ////
+//// This source file may be used and distributed without         ////
+//// restriction provided that this copyright statement is not    ////
+//// removed from the file and that any derivative work contains  ////
+//// the original copyright notice and the associated disclaimer. ////
+////                                                              ////
+//// This source file is free software; you can redistribute it   ////
+//// and/or modify it under the terms of the GNU Lesser General   ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any   ////
+//// later version.                                               ////
+////                                                              ////
+//// This source is distributed in the hope that it will be       ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
+//// PURPOSE.  See the GNU Lesser General Public License for more ////
+//// details.                                                     ////
+////                                                              ////
+//// You should have received a copy of the GNU Lesser General    ////
+//// Public License along with this source; if not, download it   ////
+//// from http://www.opencores.org/lgpl.shtml                     ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+
+`default_nettype none
+
+`timescale 1 ns / 1 ps
+
+`include "uprj_netlists.v"
+`include "spiflash.v"
+`include "mt48lc8m8a2.v"
+`include "uart_agent.v"
+
+
+`define ADDR_SPACE_UART = 32'h3001_0000;
+
+
+task user_uart_tb;
+
+reg            clock         ;
+reg            RSTB          ;
+reg            power1, power2;
+reg            power3, power4;
+
+reg            wbd_ext_cyc_i ;  // strobe/request
+reg            wbd_ext_stb_i ;  // strobe/request
+reg [31:0]     wbd_ext_adr_i ;  // address
+reg            wbd_ext_we_i  ;  // write
+reg [31:0]     wbd_ext_dat_i ;  // data output
+reg [3:0]      wbd_ext_sel_i ;  // byte enable
+
+wire [31:0]    wbd_ext_dat_o ;  // data input
+wire           wbd_ext_ack_o ;  // acknowlegement
+wire           wbd_ext_err_o ;  // error
+
+// User I/O
+wire [37:0]    io_oeb        ;
+wire [37:0]    io_out        ;
+wire [37:0]    io_in         ;
+
+wire [37:0]    mprj_io       ;
+wire [7:0]     mprj_io_0     ;
+reg            test_fail     ;
+reg [31:0]     read_data     ;
+//----------------------------------
+// Uart Configuration
+// ---------------------------------
+reg [1:0]      uart_data_bit        ;
+reg	       uart_stop_bits       ; // 0: 1 stop bit; 1: 2 stop bit;
+reg	       uart_stick_parity    ; // 1: force even parity
+reg	       uart_parity_en       ; // parity enable
+reg	       uart_even_odd_parity ; // 0: odd parity; 1: even parity
+
+reg [7:0]      uart_data            ;
+reg [15:0]     uart_divisor         ;	// divided by n * 16
+reg [15:0]     uart_timeout         ;// wait time limit
+
+reg [15:0]     uart_rx_nu           ;
+reg [15:0]     uart_tx_nu           ;
+reg [7:0]      uart_write_data [0:39];
+reg 	       uart_fifo_enable     ;	// fifo mode disable
+
+integer i,j;
+
+
+
+initial
+begin
+   uart_data_bit           = 2'b11;
+   uart_stop_bits          = 0; // 0: 1 stop bit; 1: 2 stop bit;
+   uart_stick_parity       = 0; // 1: force even parity
+   uart_parity_en          = 0; // parity enable
+   uart_even_odd_parity    = 1; // 0: odd parity; 1: even parity
+   uart_divisor            = 15;// divided by n * 16
+   uart_timeout            = 500;// wait time limit
+   uart_fifo_enable        = 0;	// fifo mode disable
+
+   #200; // Wait for reset removal
+   repeat (10) @(posedge clock);
+   $display("Monitor: Standalone User Risc Boot Test Started");
+   
+   #1;
+   //------------ SDRAM Config - 2
+   wb_user_core_write('h3000_0014,'h100_019E);
+   
+   repeat (2) @(posedge clock);
+   #1;
+   //------------ SDRAM Config - 1
+   wb_user_core_write('h3000_0010,'h2F17_2242);
+   
+   repeat (2) @(posedge clock);
+   #1;
+   // Remove all the reset
+   wb_user_core_write('h3000_0000,'h7);
+
+   repeat (2000) @(posedge app_clk);  // wait for Processor Get Ready
+   tb_uart.uart_init;
+   wb_user_core_write(`ADDR_SPACE_UART+8'h0,{3'h0,2'b00,1'b1,1'b1,1'b1});  
+   
+   
+   for (i=0; i<40; i=i+1)
+   	uart_write_data[i] = $random;
+   
+   
+     tb_top.tb_uart.control_setup (uart_data_bit, uart_stop_bits, uart_parity_en, uart_even_odd_parity, 
+	                          uart_stick_parity, uart_timeout, uart_divisor, uart_fifo_enable);
+   
+      fork
+      begin
+         for (i=0; i<40; i=i+1)
+         begin
+           $display ("\n... UART Agent Writing char %x ...", write_data[i]);
+            tb_top.tb_uart.write_char (uart_write_data[i]);
+         end
+      end
+   
+      begin
+         for (j=0; j<40; j=j+1)
+         begin
+           tb_top.tb_uart.read_char_chk(uart_write_data[j]);
+         end
+      end
+      join
+   
+      #100
+      tb_top.tb_uart.report_status(rx_nu, tx_nu);
+   
+      test_fail = 0;
+      wb_user_core_read(32'h30000018,read_data);
+
+      // Check 
+      // if all the 40 byte transmitted
+      // if all the 40 byte received
+      // if no error 
+      if(tx_nu != 40) test_fail = 1;
+      if(rx_nu != 40) test_fail = 1;
+      if(tb_top.tb_uart.err_cnt != 0) test_fail = 1;
+
+      $display("###################################################");
+      if(test_fail == 0) begin
+         `ifdef GL
+             $display("Monitor: Standalone User UART Test (GL) Passed");
+         `else
+             $display("Monitor: Standalone User UART Test (RTL) Passed");
+         `endif
+      end else begin
+          `ifdef GL
+              $display("Monitor: Standalone User UART Test (GL) Failed");
+          `else
+              $display("Monitor: Standalone User UART Test (RTL) Failed");
+          `endif
+       end
+      $display("###################################################");
+      #100
+      $finish;
+end
+
+
+digital_core u_core(
+`ifdef USE_POWER_PINS
+    .vdda1(),	// User area 1 3.3V supply
+    .vdda2(),	// User area 2 3.3V supply
+    .vssa1(),	// User area 1 analog ground
+    .vssa2(),	// User area 2 analog ground
+    .vccd1(),	// User area 1 1.8V supply
+    .vccd2(),	// User area 2 1.8v supply
+    .vssd1(),	// User area 1 digital ground
+    .vssd2(),	// User area 2 digital ground
+`endif
+    .wb_clk_i        (clock),  // System clock
+    .rtc_clk         (1'b1),  // Real-time clock
+    .wb_rst_i        (RSTB),  // Regular Reset signal
+
+    .wbd_ext_cyc_i   (wbd_ext_cyc_i),  // strobe/request
+    .wbd_ext_stb_i   (wbd_ext_stb_i),  // strobe/request
+    .wbd_ext_adr_i   (wbd_ext_adr_i),  // address
+    .wbd_ext_we_i    (wbd_ext_we_i),  // write
+    .wbd_ext_dat_i   (wbd_ext_dat_i),  // data output
+    .wbd_ext_sel_i   (wbd_ext_sel_i),  // byte enable
+
+    .wbd_ext_dat_o   (wbd_ext_dat_o),  // data input
+    .wbd_ext_ack_o   (wbd_ext_ack_o),  // acknowlegement
+    .wbd_ext_err_o   (wbd_ext_err_o),  // error
+
+ 
+    // Logic Analyzer Signals
+    .la_data_in      ('0) ,
+    .la_data_out     (),
+    .la_oenb         ('0),
+ 
+
+    // IOs
+    .io_in          (io_in)  ,
+    .io_out         (io_out) ,
+    .io_oeb         (io_oeb) ,
+
+    .user_irq       () 
+
+);
+
+//------------------------------------------------------
+//  Integrate the Serial flash with qurd support to
+//  user core using the gpio pads
+//  ----------------------------------------------------
+
+   wire flash_clk = io_out[30];
+   wire flash_csb = io_out[31];
+   tri  flash_io0 = (io_oeb[32]== 1'b0) ? io_out[32] : 1'bz;
+   tri  flash_io1 = (io_oeb[33]== 1'b0) ? io_out[33] : 1'bz;
+   tri  flash_io2 = (io_oeb[34]== 1'b0) ? io_out[34] : 1'bz;
+   tri  flash_io3 = (io_oeb[35]== 1'b0) ? io_out[35] : 1'bz;
+
+   assign io_in[32] = flash_io0;
+   assign io_in[33] = flash_io1;
+   assign io_in[34] = flash_io2;
+   assign io_in[35] = flash_io3;
+
+
+   // Quard flash
+	spiflash #(
+		.FILENAME("user_uart.hex")
+	) u_user_spiflash (
+		.csb(flash_csb),
+		.clk(flash_clk),
+		.io0(flash_io0),
+		.io1(flash_io1),
+		.io2(flash_io2),
+		.io3(flash_io3)	
+	);
+
+
+//------------------------------------------------
+// Integrate the SDRAM 8 BIT Memory
+// -----------------------------------------------
+
+wire [7:0]    Dq                 ; // SDRAM Read/Write Data Bus
+wire [0:0]    sdr_dqm            ; // SDRAM DATA Mask
+wire [1:0]    sdr_ba             ; // SDRAM Bank Select
+wire [12:0]   sdr_addr           ; // SDRAM ADRESS
+wire          sdr_cs_n           ; // chip select
+wire          sdr_cke            ; // clock gate
+wire          sdr_ras_n          ; // ras
+wire          sdr_cas_n          ; // cas
+wire          sdr_we_n           ; // write enable        
+wire          sdram_clk         ;      
+
+assign  Dq[7:0]           =  (io_oeb[7:0] == 8'h0) ? io_out [7:0] : 8'hZZ;
+assign  sdr_addr[12:0]    =    io_out [20:8]     ;
+assign  sdr_ba[1:0]       =    io_out [22:21]    ;
+assign  sdr_dqm[0]        =    io_out [23]       ;
+assign  sdr_we_n          =    io_out [24]       ;
+assign  sdr_cas_n         =    io_out [25]       ;
+assign  sdr_ras_n         =    io_out [26]       ;
+assign  sdr_cs_n          =    io_out [27]       ;
+assign  sdr_cke           =    io_out [28]       ;
+assign  sdram_clk         =    io_out [29]       ;
+assign  io_in[29]         =    sdram_clk;
+assign  #(1) io_in[7:0]   =    Dq;
+
+// to fix the sdram interface timing issue
+wire #(1) sdram_clk_d   = sdram_clk;
+
+	// SDRAM 8bit
+mt48lc8m8a2 #(.data_bits(8)) u_sdram8 (
+          .Dq                 (Dq                 ) , 
+          .Addr               (sdr_addr[11:0]     ), 
+          .Ba                 (sdr_ba             ), 
+          .Clk                (sdram_clk_d        ), 
+          .Cke                (sdr_cke            ), 
+          .Cs_n               (sdr_cs_n           ), 
+          .Ras_n              (sdr_ras_n          ), 
+          .Cas_n              (sdr_cas_n          ), 
+          .We_n               (sdr_we_n           ), 
+          .Dqm                (sdr_dqm            )
+     );
+
+
+//---------------------------
+//  UART Agent integration
+// --------------------------
+wire uart_txd,uart_rxd;
+
+assign uart_txd   = io_out[37];
+assign io_in[36]  = uart_rxd ;
+ 
+uart_agent tb_uart(
+	.mclk                (clock              ),
+	.txd                 (uart_rxd           ),
+	.rxd                 (uart_txd           )
+	);
+
+
+task wb_user_core_write;
+input [31:0] address;
+input [31:0] data;
+begin
+  repeat (1) @(posedge clock);
+  wbd_ext_adr_i =address;  // address
+  wbd_ext_we_i  ='h1;  // write
+  wbd_ext_dat_i =data;  // data output
+  wbd_ext_sel_i ='hF;  // byte enable
+  wbd_ext_cyc_i ='h1;  // strobe/request
+  wbd_ext_stb_i ='h1;  // strobe/request
+  wait(wbd_ext_ack_o == 1);
+  repeat (1) @(posedge clock);
+  wbd_ext_cyc_i ='h0;  // strobe/request
+  wbd_ext_stb_i ='h0;  // strobe/request
+  wbd_ext_adr_i ='h0;  // address
+  wbd_ext_we_i  ='h0;  // write
+  wbd_ext_dat_i ='h0;  // data output
+  wbd_ext_sel_i ='h0;  // byte enable
+  $display("DEBUG WB USER ACCESS WRITE Address : %x, Data : %x",address,data);
+  repeat (2) @(posedge clock);
+end
+endtask
+
+task  wb_user_core_read;
+input [31:0] address;
+output [31:0] data;
+reg    [31:0] data;
+begin
+  repeat (1) @(posedge clock);
+  wbd_ext_adr_i =address;  // address
+  wbd_ext_we_i  ='h0;  // write
+  wbd_ext_dat_i ='0;  // data output
+  wbd_ext_sel_i ='hF;  // byte enable
+  wbd_ext_cyc_i ='h1;  // strobe/request
+  wbd_ext_stb_i ='h1;  // strobe/request
+  wait(wbd_ext_ack_o == 1);
+  data  = wbd_ext_dat_o;  
+  repeat (1) @(posedge clock);
+  wbd_ext_cyc_i ='h0;  // strobe/request
+  wbd_ext_stb_i ='h0;  // strobe/request
+  wbd_ext_adr_i ='h0;  // address
+  wbd_ext_we_i  ='h0;  // write
+  wbd_ext_dat_i ='h0;  // data output
+  wbd_ext_sel_i ='h0;  // byte enable
+  $display("DEBUG WB USER ACCESS READ Address : %x, Data : %x",address,data);
+  repeat (2) @(posedge clock);
+end
+endtask
+
+
+
+
+////-----------------------------------------------------------------------------
+//// RISC IMEM amd DMEM Monitoring TASK
+////-----------------------------------------------------------------------------
+//logic [`SCR1_DMEM_AWIDTH-1:0]           core2imem_addr_o_r;           // DMEM address
+//logic [`SCR1_DMEM_AWIDTH-1:0]           core2dmem_addr_o_r;           // DMEM address
+//logic                                   core2dmem_cmd_o_r;
+//
+//`define RISC_CORE  user_uart_tb.u_core.u_riscv_top.i_core_top
+//
+//always@(posedge `RISC_CORE.clk) begin
+//    if(`RISC_CORE.imem2core_req_ack_i && `RISC_CORE.core2imem_req_o)
+//          core2imem_addr_o_r <= `RISC_CORE.core2imem_addr_o;
+//
+//    if(`RISC_CORE.dmem2core_req_ack_i && `RISC_CORE.core2dmem_req_o) begin
+//          core2dmem_addr_o_r <= `RISC_CORE.core2dmem_addr_o;
+//          core2dmem_cmd_o_r  <= `RISC_CORE.core2dmem_cmd_o;
+//    end
+//
+//    if(`RISC_CORE.imem2core_resp_i !=0)
+//          $display("RISCV-DEBUG => IMEM ADDRESS: %x Read Data : %x Resonse: %x", core2imem_addr_o_r,`RISC_CORE.imem2core_rdata_i,`RISC_CORE.imem2core_resp_i);
+//    if((`RISC_CORE.dmem2core_resp_i !=0) && core2dmem_cmd_o_r)
+//          $display("RISCV-DEBUG => DMEM ADDRESS: %x Write Data: %x Resonse: %x", core2dmem_addr_o_r,`RISC_CORE.core2dmem_wdata_o,`RISC_CORE.dmem2core_resp_i);
+//    if((`RISC_CORE.dmem2core_resp_i !=0) && !core2dmem_cmd_o_r)
+//          $display("RISCV-DEBUG => DMEM ADDRESS: %x READ Data : %x Resonse: %x", core2dmem_addr_o_r,`RISC_CORE.dmem2core_rdata_i,`RISC_CORE.dmem2core_resp_i);
+//end
+endmodule
+`default_nettype wire

diff --git a/verilog/rtl/digital_core/src/digital_core.sv b/verilog/rtl/digital_core/src/digital_core.sv
index 41fbf83..405df05 100644
--- a/verilog/rtl/digital_core/src/digital_core.sv
+++ b/verilog/rtl/digital_core/src/digital_core.sv

@@ -31,15 +31,18 @@
 ////        4. buswidth warning are fixed inside spi_master       ////
 ////        modified rtl files are                                ////
 ////           verilog/rtl/digital_core/src/digital_core.sv       ////
-///            verilog/rtl/digital_core/src/glbl_cfg.sv           ////
-///            verilog/rtl/lib/wb_stagging.sv                     ////
-///            verilog/rtl/syntacore/scr1/src/top/scr1_dmem_wb.sv ////
-///            verilog/rtl/syntacore/scr1/src/top/scr1_imem_wb.sv ////
-///            verilog/rtl/syntacore/scr1/src/top/scr1_top_wb.sv  ////
-///            verilog/rtl/user_project_wrapper.v                 ////
-///            verilog/rtl/wb_interconnect/src/wb_interconnect.sv ////
-///            verilog/rtl/spi_master/src/spim_clkgen.sv          ////
-///            verilog/rtl/spi_master/src/spim_ctrl.sv            ////
+////           verilog/rtl/digital_core/src/glbl_cfg.sv           ////
+////           verilog/rtl/lib/wb_stagging.sv                     ////
+////           verilog/rtl/syntacore/scr1/src/top/scr1_dmem_wb.sv ////
+////           verilog/rtl/syntacore/scr1/src/top/scr1_imem_wb.sv ////
+////           verilog/rtl/syntacore/scr1/src/top/scr1_top_wb.sv  ////
+////           verilog/rtl/user_project_wrapper.v                 ////
+////           verilog/rtl/wb_interconnect/src/wb_interconnect.sv ////
+////           verilog/rtl/spi_master/src/spim_clkgen.sv          ////
+////           verilog/rtl/spi_master/src/spim_ctrl.sv            ////
+////    0.3 - 20th June 2021, Dinesh A                            ////
+////           1. uart core is integrated                         ////
+////           2. 3rd Slave ported added to wishbone interconnect ////
 ////                                                              ////
 //////////////////////////////////////////////////////////////////////
 ////                                                              ////
@@ -188,6 +191,18 @@
 logic                           wbd_glbl_ack_i; // acknowlegement
 logic                           wbd_glbl_err_i;  // error
 
+//---------------------------------------------------------------------
+//    Global Register Wishbone Interface
+//---------------------------------------------------------------------
+logic                           wbd_uart_stb_o; // strobe/request
+logic   [7:0]                   wbd_uart_adr_o; // address
+logic                           wbd_uart_we_o;  // write
+logic   [7:0]                   wbd_uart_dat_o; // data output
+logic                           wbd_uart_sel_o; // byte enable
+logic                           wbd_uart_cyc_o ;
+logic   7:0]                    wbd_uart_dat_i; // data input
+logic                           wbd_uart_ack_i; // acknowlegement
+logic                           wbd_uart_err_i;  // error
 
 //----------------------------------------------------
 //  CPU Configuration
@@ -200,6 +215,8 @@
 logic [15:0]                       irq_lines     ;
 logic                              soft_irq      ;
 
+        .si                    ( uart_rx                 ),
+        .so                    ( uart_tx                 )
 //------------------------------------------------
 // Configuration Parameter
 //------------------------------------------------
@@ -296,12 +313,25 @@
 assign  io_oeb[34] =  !spi_en_tx;   // spi_dio2
 assign  io_oeb[35] =  !spi_en_tx;   // spi_dio3
 
+/////////////////////////////////////////////////////////
+// uart interface
+///////////////////////////////////////////////////////
+
+logic                         uart_rx                  ; 
+logic                         uart_tx                  ;
 
 // for uart
-assign  io_oeb[36] =  1'b1; // Unused
-assign  io_oeb[37] =  1'b1; // Unused
+assign  io_oeb[36] =  1'b1; // Uart RX
+assign  uart_rx    =  io_in[36];
+
+assign  io_oeb[37] =  1'b0; // Uart TX
+assign  io_out[37] =  uart_tx;
 
 
+
+/////////////////////////////////////////////////////////
+// Generating acive low wishbone reset                 
+// //////////////////////////////////////////////////////
 wire wb_rst_n = !wb_rst_i;
 
 
@@ -549,6 +579,17 @@
          .s2_wbd_we_o   (wbd_glbl_we_o  ),  
          .s2_wbd_cyc_o  (wbd_glbl_cyc_o ),
          .s2_wbd_stb_o  (wbd_glbl_stb_o )
+
+         // Slave 3 Interface
+         .s2_wbd_err_i  (1'b0           ),
+         .s2_wbd_dat_i  (wbd_uart_dat_i ),
+         .s2_wbd_ack_i  (wbd_uart_ack_i ),
+         .s2_wbd_dat_o  (wbd_uart_dat_o ),
+         .s2_wbd_adr_o  (wbd_uart_adr_o ),
+         .s2_wbd_sel_o  (wbd_uart_sel_o ),
+         .s2_wbd_we_o   (wbd_uart_we_o  ),  
+         .s2_wbd_cyc_o  (wbd_uart_cyc_o ),
+         .s2_wbd_stb_o  (wbd_uart_stb_o )
 	);
 
 glbl_cfg   u_glbl_cfg (
@@ -607,6 +648,26 @@
 
         );
 
+uart_core   u_uart_core (
+        arst_n                 (wb_rst_n                  ), // async reset
+        app_clk                (wb_clk_i                  ),
+
+        // Reg Bus Interface Signal
+       .reg_cs                 (wbd_uart_stb_o            ),
+       .reg_wr                 (wbd_uart_we_o             ),
+       .reg_addr               (wbd_uart_adr_o[5:2]       ),
+       .reg_wdata              (wbd_uart_dat_o[7:0]       ),
+       .reg_be                 (wbd_uart_sel_o            ),
+
+       // Outputs
+       .reg_rdata              (wbd_uart_dat_i[7:0]       ),
+       .reg_ack                (wbd_uart_ack_i            ),
+
+       // Line Interface
+        .si                    ( uart_rx                 ),
+        .so                    ( uart_tx                 )
+
+     );
 
 
 endmodule : digital_core

diff --git a/verilog/rtl/lib/reset_sync.sv b/verilog/rtl/lib/reset_sync.sv
new file mode 100644
index 0000000..ea99a4a
--- /dev/null
+++ b/verilog/rtl/lib/reset_sync.sv

@@ -0,0 +1,83 @@
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+////  Active low reset synchronization                           ////
+////                                                              ////
+////  This file is part of the yifive cores project               ////
+////  http://www.opencores.org/cores/yifive/                      ////
+////                                                              ////
+////  Description:                                                ////
+////     Synchronize the active low reset to destination clock    ////
+////                                                              ////
+////  To Do:                                                      ////
+////    nothing                                                   ////
+////                                                              ////
+////  Author(s):                                                  ////
+////      - Dinesh Annayya, dinesha@opencores.org                 ////
+////                                                              ////
+////  Revision :                                                  ////
+////     v0:    June 17, 2021, Dinesh A                           ////
+////             Initial version                                  ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+//// Copyright (C) 2000 Authors and OPENCORES.ORG                 ////
+////                                                              ////
+//// This source file may be used and distributed without         ////
+//// restriction provided that this copyright statement is not    ////
+//// removed from the file and that any derivative work contains  ////
+//// the original copyright notice and the associated disclaimer. ////
+////                                                              ////
+//// This source file is free software; you can redistribute it   ////
+//// and/or modify it under the terms of the GNU Lesser General   ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any   ////
+//// later version.                                               ////
+////                                                              ////
+//// This source is distributed in the hope that it will be       ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
+//// PURPOSE.  See the GNU Lesser General Public License for more ////
+//// details.                                                     ////
+////                                                              ////
+//// You should have received a copy of the GNU Lesser General    ////
+//// Public License along with this source; if not, download it   ////
+//// from http://www.opencores.org/lgpl.shtml                     ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+
+module reset_sync   (
+	      scan_mode  ,
+              dclk       , // Destination clock domain
+	      arst_n     , // active low async reset
+              srst_n 
+          );
+
+parameter WIDTH = 1;
+
+input    scan_mode  ; // test mode
+input    dclk       ; // Destination clock
+input    arst_n     ; // Async Reset
+input    srst_n     ; // Sync Reset w.r.t dclk
+
+
+reg      in_data_s  ; // One   Cycle sync 
+reg      in_data_2s ; // two   Cycle sync 
+
+assign srst_n =  (scan_mode) ? arst_n : in_data_2s;
+
+always @(negedge arst_n  or posedge dclk)
+begin
+   if(arst_n == 1'b0)
+   begin
+      in_data_s  <= 1'b0;
+      in_data_2s <= 1'b0;
+   end
+   else
+   begin
+      in_data_s  <= 1'b1;
+      in_data_2s <= in_data_s;
+   end
+end
+
+
+endmodule

diff --git a/verilog/rtl/uart/src/uart_cfg.sv b/verilog/rtl/uart/src/uart_cfg.sv
new file mode 100644
index 0000000..a979c77
--- /dev/null
+++ b/verilog/rtl/uart/src/uart_cfg.sv

@@ -0,0 +1,387 @@
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+////  UART Configuration                                          ////
+////                                                              ////
+////  This file is part of the YIFive cores project               ////
+////  http://www.opencores.org/cores/yifive/                      ////
+////                                                              ////
+////  Description                                                 ////
+////                                                              ////
+////  To Do:                                                      ////
+////    nothing                                                   ////
+////                                                              ////
+////  Author(s):                                                  ////
+////      - Dinesh Annayya, dinesha@opencores.org                 ////
+////                                                              ////
+////  Revision :                                                  //// 
+////    0.1 - 20th June 2021, Dinesh A                            ////
+////        1. initial version picked from                        ////
+////          http://www.opencores.org/cores/oms8051mini          ////
+////    0.2 - 20th June 2021, Dinesh A                            ////
+////          tx and rx buffer status added into reg7 and reg8    ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+//// Copyright (C) 2000 Authors and OPENCORES.ORG                 ////
+////                                                              ////
+//// This source file may be used and distributed without         ////
+//// restriction provided that this copyright statement is not    ////
+//// removed from the file and that any derivative work contains  ////
+//// the original copyright notice and the associated disclaimer. ////
+////                                                              ////
+//// This source file is free software; you can redistribute it   ////
+//// and/or modify it under the terms of the GNU Lesser General   ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any   ////
+//// later version.                                               ////
+////                                                              ////
+//// This source is distributed in the hope that it will be       ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
+//// PURPOSE.  See the GNU Lesser General Public License for more ////
+//// details.                                                     ////
+////                                                              ////
+//// You should have received a copy of the GNU Lesser General    ////
+//// Public License along with this source; if not, download it   ////
+//// from http://www.opencores.org/lgpl.shtml                     ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+
+module uart_cfg (
+
+             mclk,
+             reset_n,
+
+        // Reg Bus Interface Signal
+             reg_cs,
+             reg_wr,
+             reg_addr,
+             reg_wdata,
+             reg_be,
+
+            // Outputs
+             reg_rdata,
+             reg_ack,
+
+         // Uart Tx fifo interface
+             tx_fifo_full,
+             tx_fifo_fspace,
+             tx_fifo_wr_en,
+             tx_fifo_data,
+
+         // Uart Rx fifo interface
+             rx_fifo_empty,
+             rx_fifo_dval ,
+             rx_fifo_rd_en,
+             rx_fifo_data ,
+
+       // configuration
+             cfg_tx_enable,
+             cfg_rx_enable,
+             cfg_stop_bit ,
+             cfg_pri_mod  ,
+             cfg_baud_16x ,
+
+             frm_error_o,
+             par_error_o,
+             rx_fifo_full_err_o
+
+        );
+
+
+
+input            mclk;
+input            reset_n;
+
+//--------------------------------
+// Uart Tx fifo interface
+//--------------------------------
+input            tx_fifo_full;
+input [4:0]      tx_fifo_fspace        ; // Total Tx fifo Free Space
+output           tx_fifo_wr_en;
+output [7:0]     tx_fifo_data;
+
+//--------------------------------
+// Uart Rx fifo interface
+//--------------------------------
+input            rx_fifo_empty;
+wire [4:0]       rx_fifo_dval          ; // Total Rx fifo Data Available
+output           rx_fifo_rd_en;
+input [7:0]      rx_fifo_data;
+
+//----------------------------------
+// configuration
+//----------------------------------
+output           cfg_tx_enable       ; // Tx Enable
+output           cfg_rx_enable       ; // Rx Enable
+output           cfg_stop_bit        ; // 0 -> 1 Stop, 1 -> 2 Stop
+output [1:0]     cfg_pri_mod         ; // priority mode, 0 -> nop, 1 -> Even, 2 -> Odd
+output [11:0]    cfg_baud_16x        ; // 16x Baud clock config
+
+input            frm_error_o         ; // framing error
+input            par_error_o         ; // par error
+input            rx_fifo_full_err_o  ; // rx fifo full error
+
+//---------------------------------
+// Reg Bus Interface Signal
+//---------------------------------
+input             reg_cs         ;
+input             reg_wr         ;
+input [3:0]       reg_addr       ;
+input [7:0]       reg_wdata      ;
+input             reg_be         ;
+
+// Outputs
+output [7:0]      reg_rdata      ;
+output            reg_ack        ;
+
+
+
+//-----------------------------------------------------------------------
+// Internal Wire Declarations
+//-----------------------------------------------------------------------
+
+wire           sw_rd_en;
+wire           sw_wr_en;
+wire  [3:0]    sw_addr ; // addressing 16 registers
+wire           wr_be   ;
+
+reg   [7:0]  reg_rdata      ;
+reg           reg_ack     ;
+
+wire [7:0]    reg_0;  // Software_Reg_0
+wire [7:0]    reg_1;  // Software-Reg_1
+wire [7:0]    reg_2;  // Software-Reg_2
+wire [7:0]    reg_3;  // Software-Reg_3
+wire [7:0]    reg_4;  // Software-Reg_4
+wire [7:0]    reg_5;  // Software-Reg_5
+wire [7:0]    reg_6;  // Software-Reg_6
+wire [7:0]    reg_7;  // Software-Reg_7
+wire [7:0]    reg_8;  // Software-Reg_8
+wire [7:0]    reg_9;  // Software-Reg_9
+wire [7:0]    reg_10; // Software-Reg_10
+wire [7:0]    reg_11; // Software-Reg_11
+wire [7:0]    reg_12; // Software-Reg_12
+wire [7:0]    reg_13; // Software-Reg_13
+wire [7:0]    reg_14; // Software-Reg_14
+wire [7:0]    reg_15; // Software-Reg_15
+reg  [7:0]    reg_out;
+
+//-----------------------------------------------------------------------
+// Main code starts here
+//-----------------------------------------------------------------------
+
+//-----------------------------------------------------------------------
+// Internal Logic Starts here
+//-----------------------------------------------------------------------
+    assign sw_addr       = reg_addr [3:0];
+    assign sw_rd_en      = reg_cs & !reg_wr;
+    assign sw_wr_en      = reg_cs & reg_wr;
+    assign wr_be         = reg_be;
+
+
+//-----------------------------------------------------------------------
+// Read path mux
+//-----------------------------------------------------------------------
+
+always @ (posedge mclk or negedge reset_n)
+begin : preg_out_Seq
+   if (reset_n == 1'b0)
+   begin
+      reg_rdata [7:0]  <= 8'h00;
+      reg_ack          <= 1'b0;
+   end
+   else if (sw_rd_en && !reg_ack) 
+   begin
+      reg_rdata [7:0]  <= reg_out [7:0];
+      reg_ack          <= 1'b1;
+   end
+   else if (sw_wr_en && !reg_ack) 
+      reg_ack          <= 1'b1;
+   else
+   begin
+      reg_ack        <= 1'b0;
+   end
+end
+
+
+//-----------------------------------------------------------------------
+// register read enable and write enable decoding logic
+//-----------------------------------------------------------------------
+wire   sw_wr_en_0 = sw_wr_en & (sw_addr == 4'h0);
+wire   sw_rd_en_0 = sw_rd_en & (sw_addr == 4'h0);
+wire   sw_wr_en_1 = sw_wr_en & (sw_addr == 4'h1);
+wire   sw_rd_en_1 = sw_rd_en & (sw_addr == 4'h1);
+wire   sw_wr_en_2 = sw_wr_en & (sw_addr == 4'h2);
+wire   sw_rd_en_2 = sw_rd_en & (sw_addr == 4'h2);
+wire   sw_wr_en_3 = sw_wr_en & (sw_addr == 4'h3);
+wire   sw_rd_en_3 = sw_rd_en & (sw_addr == 4'h3);
+wire   sw_wr_en_4 = sw_wr_en & (sw_addr == 4'h4);
+wire   sw_rd_en_4 = sw_rd_en & (sw_addr == 4'h4);
+wire   sw_wr_en_5 = sw_wr_en & (sw_addr == 4'h5);
+wire   sw_rd_en_5 = sw_rd_en & (sw_addr == 4'h5);
+wire   sw_wr_en_6 = sw_wr_en & (sw_addr == 4'h6);
+wire   sw_rd_en_6 = sw_rd_en & (sw_addr == 4'h6);
+wire   sw_wr_en_7 = sw_wr_en & (sw_addr == 4'h7);
+wire   sw_rd_en_7 = sw_rd_en & (sw_addr == 4'h7);
+wire   sw_wr_en_8 = sw_wr_en & (sw_addr == 4'h8);
+wire   sw_rd_en_8 = sw_rd_en & (sw_addr == 4'h8);
+wire   sw_wr_en_9 = sw_wr_en & (sw_addr == 4'h9);
+wire   sw_rd_en_9 = sw_rd_en & (sw_addr == 4'h9);
+wire   sw_wr_en_10 = sw_wr_en & (sw_addr == 4'hA);
+wire   sw_rd_en_10 = sw_rd_en & (sw_addr == 4'hA);
+wire   sw_wr_en_11 = sw_wr_en & (sw_addr == 4'hB);
+wire   sw_rd_en_11 = sw_rd_en & (sw_addr == 4'hB);
+wire   sw_wr_en_12 = sw_wr_en & (sw_addr == 4'hC);
+wire   sw_rd_en_12 = sw_rd_en & (sw_addr == 4'hC);
+wire   sw_wr_en_13 = sw_wr_en & (sw_addr == 4'hD);
+wire   sw_rd_en_13 = sw_rd_en & (sw_addr == 4'hD);
+wire   sw_wr_en_14 = sw_wr_en & (sw_addr == 4'hE);
+wire   sw_rd_en_14 = sw_rd_en & (sw_addr == 4'hE);
+wire   sw_wr_en_15 = sw_wr_en & (sw_addr == 4'hF);
+wire   sw_rd_en_15 = sw_rd_en & (sw_addr == 4'hF);
+
+
+always @( *)
+begin : preg_sel_Com
+
+  reg_out [7:0] = 8'd0;
+
+  case (sw_addr [3:0])
+    4'b0000 : reg_out [7:0] = reg_0 [7:0];     
+    4'b0001 : reg_out [7:0] = reg_1 [7:0];    
+    4'b0010 : reg_out [7:0] = reg_2 [7:0];     
+    4'b0011 : reg_out [7:0] = reg_3 [7:0];    
+    4'b0100 : reg_out [7:0] = reg_4 [7:0];    
+    4'b0101 : reg_out [7:0] = reg_5 [7:0];    
+    4'b0110 : reg_out [7:0] = reg_6 [7:0];    
+    4'b0111 : reg_out [7:0] = reg_7 [7:0];    
+    4'b1000 : reg_out [7:0] = reg_8 [7:0];    
+    4'b1001 : reg_out [7:0] = reg_9 [7:0];    
+    4'b1010 : reg_out [7:0] = reg_10 [7:0];   
+    4'b1011 : reg_out [7:0] = reg_11 [7:0];   
+    4'b1100 : reg_out [7:0] = reg_12 [7:0];   
+    4'b1101 : reg_out [7:0] = reg_13 [7:0];
+    4'b1110 : reg_out [7:0] = reg_14 [7:0];
+    4'b1111 : reg_out [7:0] = reg_15 [7:0]; 
+  endcase
+end
+
+
+
+//-----------------------------------------------------------------------
+// Individual register assignments
+//-----------------------------------------------------------------------
+// Logic for Register 0 : uart Control Register
+//-----------------------------------------------------------------------
+wire [1:0]   cfg_pri_mod     = reg_0[4:3]; // priority mode, 0 -> nop, 1 -> Even, 2 -> Odd
+wire         cfg_stop_bit    = reg_0[2];   // 0 -> 1 Stop, 1 -> 2 Stop
+wire         cfg_rx_enable   = reg_0[1];   // Rx Enable
+wire         cfg_tx_enable   = reg_0[0];   // Tx Enable
+
+generic_register #(5,0  ) u_uart_ctrl_be0 (
+	      .we            ({5{sw_wr_en_0 & 
+                                 wr_be   }}  ),		 
+	      .data_in       (reg_wdata[4:0]    ),
+	      .reset_n       (reset_n           ),
+	      .clk           (mclk              ),
+	      
+	      //List of Outs
+	      .data_out      (reg_0[4:0]        )
+          );
+
+
+assign reg_0[7:5] = 3'h0;
+
+//-----------------------------------------------------------------------
+// Logic for Register 1 : uart interrupt status
+//-----------------------------------------------------------------------
+stat_register u_intr_bit0 (
+		 //inputs
+		 . clk        (mclk            ),
+		 . reset_n    (reset_n         ),
+		 . cpu_we     (sw_wr_en_1 &
+                               wr_be        ),		 
+		 . cpu_ack    (reg_wdata[0]    ),
+		 . hware_req  (frm_error_o     ),
+		 
+		 //outputs
+		 . data_out   (reg_1[0]        )
+		 );
+
+stat_register u_intr_bit1 (
+		 //inputs
+		 . clk        (mclk            ),
+		 . reset_n    (reset_n         ),
+		 . cpu_we     (sw_wr_en_1 &
+                               wr_be        ),		 
+		 . cpu_ack    (reg_wdata[1]    ),
+		 . hware_req  (par_error_o     ),
+		 
+		 //outputs
+		 . data_out   (reg_1[1]        )
+		 );
+
+stat_register u_intr_bit2 (
+		 //inputs
+		 . clk        (mclk                ),
+		 . reset_n    (reset_n             ),
+		 . cpu_we     (sw_wr_en_1 &
+                               wr_be            ),		 
+		 . cpu_ack    (reg_wdata[2]        ),
+		 . hware_req  (rx_fifo_full_err_o  ),
+		 
+		 //outputs
+		 . data_out   (reg_1[2]            )
+		 );
+
+assign reg_1[7:3] = 5'h0;
+
+
+//-----------------------------------------------------------------------
+// Logic for Register 2 :  Baud Rate Control
+//-----------------------------------------------------------------------
+wire [11:0]   cfg_baud_16x    = {reg_3[3:0],reg_2[7:0]}; 
+
+generic_register #(8,0  ) u_uart_ctrl_reg2 (
+	      .we            ({8{sw_wr_en_2 & 
+                                 wr_be   }}  ),		 
+	      .data_in       (reg_wdata[7:0]    ),
+	      .reset_n       (reset_n           ),
+	      .clk           (mclk              ),
+	      
+	      //List of Outs
+	      .data_out      (reg_2[7:0]        )
+          );
+
+generic_register #(4,0  ) u_uart_ctrl_reg3 (
+	      .we            ({4{sw_wr_en_3 & 
+                                 wr_be   }}  ),		 
+	      .data_in       (reg_wdata[3:0]    ),
+	      .reset_n       (reset_n           ),
+	      .clk           (mclk              ),
+	      
+	      //List of Outs
+	      .data_out      (reg_3[3:0]        )
+          );
+
+assign reg_3[7:4] = 4'h0;
+
+
+// reg-4  status
+//
+assign reg_4[7:0] = {6'h0,rx_fifo_empty,tx_fifo_full};
+
+// reg_5 is tx_fifo wr
+assign tx_fifo_wr_en  = sw_wr_en_5 & reg_ack & !tx_fifo_full;
+assign tx_fifo_data   = reg_wdata[7:0];
+
+// reg_6 is rx_fifo read
+// rx_fifo read data
+assign reg_6[7:0] = {rx_fifo_data};
+assign  rx_fifo_rd_en = sw_rd_en_6 & reg_ack & !rx_fifo_empty;
+
+assign reg_7[7:0] = {3'h0,tx_fifo_fspace}; // tx fifo free space
+assign reg_8[7:0] = {3'h0,rx_fifo_dval};   // rx fifo data available
+
+endmodule

diff --git a/verilog/rtl/uart/src/uart_core.sv b/verilog/rtl/uart/src/uart_core.sv
new file mode 100644
index 0000000..d318e3f
--- /dev/null
+++ b/verilog/rtl/uart/src/uart_core.sv

@@ -0,0 +1,320 @@
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+////  UART CORE with TX/RX 16 Byte Buffer                         ////
+////                                                              ////
+////  This file is part of the YIFive cores project               ////
+////  http://www.opencores.org/cores/yifive/                      ////
+////                                                              ////
+////  Description                                                 ////
+////                                                              ////
+////  To Do:                                                      ////
+////    nothing                                                   ////
+////                                                              ////
+////  Author(s):                                                  ////
+////      - Dinesh Annayya, dinesha@opencores.org                 ////
+////                                                              ////
+////  Revision :                                                  ////
+////    0.1 - 20th June 2021, Dinesh A                            ////
+////        1. initial version picked from                        ////
+////          http://www.opencores.org/cores/oms8051mini          ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+//// Copyright (C) 2000 Authors and OPENCORES.ORG                 ////
+////                                                              ////
+//// This source file may be used and distributed without         ////
+//// restriction provided that this copyright statement is not    ////
+//// removed from the file and that any derivative work contains  ////
+//// the original copyright notice and the associated disclaimer. ////
+////                                                              ////
+//// This source file is free software; you can redistribute it   ////
+//// and/or modify it under the terms of the GNU Lesser General   ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any   ////
+//// later version.                                               ////
+////                                                              ////
+//// This source is distributed in the hope that it will be       ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
+//// PURPOSE.  See the GNU Lesser General Public License for more ////
+//// details.                                                     ////
+////                                                              ////
+//// You should have received a copy of the GNU Lesser General    ////
+//// Public License along with this source; if not, download it   ////
+//// from http://www.opencores.org/lgpl.shtml                     ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+
+module uart_core 
+
+     (  
+
+        arst_n  , // async reset
+        app_clk ,
+
+        // Reg Bus Interface Signal
+        reg_cs,
+        reg_wr,
+        reg_addr,
+        reg_wdata,
+        reg_be,
+
+        // Outputs
+        reg_rdata,
+        reg_ack,
+
+       // Line Interface
+        si,
+        so
+
+     );
+
+
+
+
+parameter W  = 8'd8;
+parameter DP = 8'd16;
+parameter AW = (DP == 2)   ? 1 : 
+	       (DP == 4)   ? 2 :
+               (DP == 8)   ? 3 :
+               (DP == 16)  ? 4 :
+               (DP == 32)  ? 5 :
+               (DP == 64)  ? 6 :
+               (DP == 128) ? 7 :
+               (DP == 256) ? 8 : 0;
+
+
+
+input        arst_n               ; // async reset
+input        app_clk              ; // application clock
+
+//---------------------------------
+// Reg Bus Interface Signal
+//---------------------------------
+input             reg_cs         ;
+input             reg_wr         ;
+input [3:0]       reg_addr       ;
+input [7:0]       reg_wdata      ;
+input             reg_be         ;
+
+// Outputs
+output [7:0]      reg_rdata      ;
+output            reg_ack        ;
+
+// Line Interface
+input         si                  ; // uart si
+output        so                  ; // uart so
+
+// Wire Declaration
+wire            app_reset_n       ;
+wire            line_reset_n      ;
+
+wire [W-1: 0]   tx_fifo_rd_data;
+wire [W-1: 0]   rx_fifo_wr_data;
+wire [W-1: 0]   app_rxfifo_data;
+wire [W-1: 0]   app_txfifo_data;
+wire [1  : 0]   error_ind;
+
+// Wire 
+wire            cfg_tx_enable        ; // Tx Enable
+wire            cfg_rx_enable        ; // Rx Enable
+wire            cfg_stop_bit         ; // 0 -> 1 Stop, 1 -> 2 Stop
+wire   [1:0]    cfg_pri_mod          ; // priority mode, 0 -> nop, 1 -> Even, 2 -> Odd
+
+wire            frm_error_o          ; // framing error
+wire            par_error_o          ; // par error
+wire            rx_fifo_full_err_o   ; // rx fifo full error
+
+wire   [11:0]   cfg_baud_16x         ; // 16x Baud clock generation
+wire            rx_fifo_wr_full      ;
+wire           app_rxfifo_empty      ;
+
+wire [AW:0]    tx_fifo_fspace        ; // Total Tx fifo Free Space
+wire [AW:0]    rx_fifo_dval          ; // Total Rx fifo Data Available
+
+uart_cfg u_cfg (
+
+             . mclk                (app_clk),
+             . reset_n             (app_reset_n),
+
+        // Reg Bus Interface Signal
+             . reg_cs              (reg_cs),
+             . reg_wr              (reg_wr),
+             . reg_addr            (reg_addr),
+             . reg_wdata           (reg_wdata),
+             . reg_be              (reg_be),
+
+            // Outputs
+            . reg_rdata           (reg_rdata),
+            . reg_ack             (reg_ack),
+
+
+       // configuration
+            . cfg_tx_enable       (cfg_tx_enable),
+            . cfg_rx_enable       (cfg_rx_enable),
+            . cfg_stop_bit        (cfg_stop_bit),
+            . cfg_pri_mod         (cfg_pri_mod),
+
+            . cfg_baud_16x        (cfg_baud_16x),  
+
+            . tx_fifo_full        (app_tx_fifo_full),
+             .tx_fifo_fspace      (tx_fifo_fspace ),
+            . tx_fifo_wr_en       (tx_fifo_wr_en),
+            . tx_fifo_data        (app_txfifo_data),
+
+            . rx_fifo_empty       (app_rxfifo_empty),
+             .rd_fifo_dval        (rx_fifo_dval   ),
+            . rx_fifo_rd_en       (app_rxfifo_rd_en),
+            . rx_fifo_data        (app_rxfifo_data) ,
+
+            . frm_error_o         (frm_error_o),
+            . par_error_o         (par_error_o),
+            . rx_fifo_full_err_o  (rx_fifo_full_err_o)
+
+        );
+
+
+//##############################################################
+// 16x Baud clock generation
+// Example: to generate 19200 Baud clock from 50Mhz Link clock
+//    50 * 1000 * 1000 / (2 + cfg_baud_16x) = 19200 * 16
+//    cfg_baud_16x = 0xA0 (160)
+//###############################################################
+
+wire line_clk_16x;
+
+clk_ctl #(11) u_clk_ctl (
+   // Outputs
+       .clk_o          (line_clk_16x),
+
+   // Inputs
+       .mclk           (app_clk),
+       .reset_n        (app_reset_n), 
+       .clk_div_ratio  (cfg_baud_16x)
+   );
+
+//###################################
+// Application Reset Synchronization
+//###################################
+reset_sync  u_app_rst (
+	      .scan_mode  (1'b0           ),
+              .dclk       (app_clk        ), // Destination clock domain
+	      .arst_n     (arst_n         ), // active low async reset
+              .srst_n     (app_reset_n    )
+          );
+
+//###################################
+// Line Reset Synchronization
+//###################################
+reset_sync  u_line_rst (
+	      .scan_mode  (1'b0           ),
+              .dclk       (line_clk_16x   ), // Destination clock domain
+	      .arst_n     (arst_n         ), // active low async reset
+              .srst_n     (line_reset_n   )
+          );
+
+
+uart_txfsm u_txfsm (
+               .reset_n           ( line_reset_n      ),
+               .baud_clk_16x      ( line_clk_16x      ),
+
+               .cfg_tx_enable     ( cfg_tx_enable     ),
+               .cfg_stop_bit      ( cfg_stop_bit      ),
+               .cfg_pri_mod       ( cfg_pri_mod       ),
+
+       // FIFO control signal
+               .fifo_empty        ( tx_fifo_rd_empty  ),
+               .fifo_rd           ( tx_fifo_rd        ),
+               .fifo_data         ( tx_fifo_rd_data   ),
+
+          // Line Interface
+               .so                ( so                )
+          );
+
+
+uart_rxfsm u_rxfsm (
+               .reset_n           (  line_reset_n     ),
+               .baud_clk_16x      (  line_clk_16x     ) ,
+
+               .cfg_rx_enable     (  cfg_rx_enable    ),
+               .cfg_stop_bit      (  cfg_stop_bit     ),
+               .cfg_pri_mod       (  cfg_pri_mod      ),
+
+               .error_ind         (  error_ind        ),
+
+       // FIFO control signal
+               .fifo_aval        ( !rx_fifo_wr_full  ),
+               .fifo_wr          ( rx_fifo_wr        ),
+               .fifo_data        ( rx_fifo_wr_data   ),
+
+          // Line Interface
+               .si               (si_ss              )
+          );
+
+async_fifo_th #(W,DP,0,0) u_rxfifo (                  
+               .wr_clk             (line_clk_16x       ),
+               .wr_reset_n         (line_reset_n       ),
+               .wr_en              (rx_fifo_wr         ),
+               .wr_data            (rx_fifo_wr_data    ),
+               .full               (rx_fifo_wr_full    ), // sync'ed to wr_clk
+               .wr_total_free_space(                   ),
+
+               .rd_clk             (app_clk            ),
+               .rd_reset_n         (app_reset_n        ),
+               .rd_en              (app_rxfifo_rd_en   ),
+               .empty              (app_rxfifo_empty   ),  // sync'ed to rd_clk
+               .rd_total_aval      (rx_fifo_dval        ),
+               .rd_data            (app_rxfifo_data    )
+                );
+
+async_fifo_th #(W,DP,0,0) u_txfifo  (
+               .wr_clk             (app_clk            ),
+               .wr_reset_n         (app_reset_n        ),
+               .wr_en              (tx_fifo_wr_en      ),
+               .wr_data            (app_txfifo_data    ),
+               .full               (app_tx_fifo_full   ), // sync'ed to wr_clk
+               .wr_total_free_space(tx_fifo_fspace     ),
+
+               .rd_clk             (line_clk_16x       ),
+               .rd_reset_n         (line_reset_n       ),
+               .rd_en              (tx_fifo_rd         ),
+               .empty              (tx_fifo_rd_empty   ),  // sync'ed to rd_clk
+               .rd_total_aval      (                   ),
+               .rd_data            (tx_fifo_rd_data    )
+                   );
+
+
+double_sync_low   u_si_sync (
+               .in_data           ( si                ),
+               .out_clk           (line_clk_16x       ),
+               .out_rst_n         (line_reset_n       ),
+               .out_data          (si_ss              ) 
+          );
+
+wire   frm_error          = (error_ind == 2'b01);
+wire   par_error          = (error_ind == 2'b10);
+wire   rx_fifo_full_err   = (error_ind == 2'b11);
+
+double_sync_low   u_frm_err (
+               .in_data           ( frm_error        ),
+               .out_clk           ( app_clk          ),
+               .out_rst_n         ( app_reset_n      ),
+               .out_data          ( frm_error_o      ) 
+          );
+
+double_sync_low   u_par_err (
+               .in_data           ( par_error        ),
+               .out_clk           ( app_clk          ),
+               .out_rst_n         ( app_reset_n      ),
+               .out_data          ( par_error_o      ) 
+          );
+
+double_sync_low   u_rxfifo_err (
+               .in_data           ( rx_fifo_full_err ),
+               .out_clk           ( app_clk          ),
+               .out_rst_n         ( app_reset_n      ),
+               .out_data          ( rx_fifo_full_err_o  ) 
+          );
+
+
+endmodule

diff --git a/verilog/rtl/uart/src/uart_rxfsm.sv b/verilog/rtl/uart/src/uart_rxfsm.sv
new file mode 100644
index 0000000..e7dea59
--- /dev/null
+++ b/verilog/rtl/uart/src/uart_rxfsm.sv

@@ -0,0 +1,203 @@
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+////  UART RX FSM                                                 ////
+////                                                              ////
+////  This file is part of the YIFive cores project               ////
+////  http://www.opencores.org/cores/yifive/                      ////
+////                                                              ////
+////  Description                                                 ////
+////                                                              ////
+////  To Do:                                                      ////
+////    nothing                                                   ////
+////                                                              ////
+////  Author(s):                                                  ////
+////      - Dinesh Annayya, dinesha@opencores.org                 ////
+////                                                              ////
+////  Revision :                                                  //// 
+////    0.1 - 20th June 2021, Dinesh A                            ////
+////        1. initial version picked from                        ////
+////          http://www.opencores.org/cores/oms8051mini          ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+//// Copyright (C) 2000 Authors and OPENCORES.ORG                 ////
+////                                                              ////
+//// This source file may be used and distributed without         ////
+//// restriction provided that this copyright statement is not    ////
+//// removed from the file and that any derivative work contains  ////
+//// the original copyright notice and the associated disclaimer. ////
+////                                                              ////
+//// This source file is free software; you can redistribute it   ////
+//// and/or modify it under the terms of the GNU Lesser General   ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any   ////
+//// later version.                                               ////
+////                                                              ////
+//// This source is distributed in the hope that it will be       ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
+//// PURPOSE.  See the GNU Lesser General Public License for more ////
+//// details.                                                     ////
+////                                                              ////
+//// You should have received a copy of the GNU Lesser General    ////
+//// Public License along with this source; if not, download it   ////
+//// from http://www.opencores.org/lgpl.shtml                     ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+
+module uart_rxfsm (
+             reset_n        ,
+             baud_clk_16x   ,
+
+             cfg_rx_enable  ,
+             cfg_stop_bit   ,
+             cfg_pri_mod    ,
+
+             error_ind      ,
+
+       // FIFO control signal
+             fifo_aval      ,
+             fifo_wr        ,
+             fifo_data      ,
+
+          // Line Interface
+             si  
+          );
+
+
+input             reset_n        ; // active low reset signal
+input             baud_clk_16x   ; // baud clock-16x
+
+input             cfg_rx_enable  ; // transmit interface enable
+input             cfg_stop_bit   ; // stop bit 
+                                   // 0 --> 1 stop, 1 --> 2 Stop
+input   [1:0]     cfg_pri_mod    ;// Priority Mode
+                                   // 2'b00 --> None
+                                   // 2'b10 --> Even priority
+                                   // 2'b11 --> Odd priority
+
+output [1:0]      error_ind     ; // 2'b00 --> Normal
+                                  // 2'b01 --> framing error
+                                  // 2'b10 --> parity error
+                                  // 2'b11 --> fifo full
+//--------------------------------------
+//   FIFO control signal
+//--------------------------------------
+input             fifo_aval      ; // fifo empty
+output            fifo_wr        ; // fifo write, assumed no back to back write
+output  [7:0]     fifo_data      ; // fifo write data
+
+// Line Interface
+input             si             ;  // rxd pin
+
+
+
+reg     [7:0]    fifo_data       ; // fifo write data
+reg              fifo_wr         ; // fifo write 
+reg    [1:0]     error_ind       ; 
+reg    [2:0]     cnt             ;
+reg    [3:0]     offset          ; // free-running counter from 0 - 15
+reg    [3:0]     rxpos           ; // stable rx position
+reg    [2:0]     rxstate         ;
+
+parameter idle_st      = 3'b000;
+parameter xfr_start    = 3'b001;
+parameter xfr_data_st  = 3'b010;
+parameter xfr_pri_st   = 3'b011;
+parameter xfr_stop_st1 = 3'b100;
+parameter xfr_stop_st2 = 3'b101;
+
+
+always @(negedge reset_n or posedge baud_clk_16x) begin
+   if(reset_n == 0) begin
+      rxstate   <= 3'b0;
+      offset    <= 4'b0;
+      rxpos     <= 4'b0;
+      cnt       <= 3'b0;
+      error_ind <= 2'b0;
+      fifo_wr   <= 1'b0;
+      fifo_data <= 8'h0;
+   end
+   else begin
+      offset     <= offset + 1;
+      case(rxstate)
+       idle_st   : begin
+            if(!si) begin // Start indication
+               if(fifo_aval && cfg_rx_enable) begin
+                 rxstate   <=   xfr_start;
+                 cnt       <=   0;
+                 rxpos     <=   offset + 8; // Assign center rxoffset
+                 error_ind <= 2'b00;
+               end
+               else begin
+                  error_ind <= 2'b11; // fifo full error indication
+               end
+            end else begin
+               error_ind <= 2'b00; // Reset Error
+            end
+         end
+      xfr_start : begin
+            // Make Sure that minimum 8 cycle low is detected
+            if(cnt < 7 && si) begin // Start indication
+               rxstate <=   idle_st;
+            end
+            else if(cnt == 7 && !si) begin // Start indication
+                rxstate <=   xfr_data_st;
+                cnt     <=   0;
+            end else begin
+              cnt  <= cnt +1;
+            end
+         end
+      xfr_data_st : begin
+             if(rxpos == offset) begin
+                fifo_data[cnt] <= si;
+                cnt            <= cnt+1;
+                if(cnt == 7) begin
+                   fifo_wr <= 1;
+                   if(cfg_pri_mod == 2'b00)  // No Priority
+                       rxstate <=   xfr_stop_st1;
+                   else rxstate <= xfr_pri_st;  
+                end
+             end
+          end
+       xfr_pri_st   : begin
+            fifo_wr <= 0;
+            if(rxpos == offset) begin
+               if(cfg_pri_mod == 2'b10)  // even priority
+                  if( si != ^fifo_data) error_ind <= 2'b10;
+               else  // Odd Priority
+                  if( si != ~(^fifo_data)) error_ind <= 2'b10;
+               rxstate <=   xfr_stop_st1;
+            end
+         end
+       xfr_stop_st1  : begin
+          fifo_wr <= 0;
+          if(rxpos == offset) begin
+             if(si) begin
+               if(cfg_stop_bit) // Two Stop bit
+                  rxstate <=   xfr_stop_st2;
+               else   
+                  rxstate <=   idle_st;
+             end else begin // Framing error
+                error_ind <= 2'b01;
+                rxstate   <=   idle_st;
+             end
+          end
+       end
+       xfr_stop_st2  : begin
+          if(rxpos == offset) begin
+             if(si) begin
+                rxstate <=   idle_st;
+             end else begin // Framing error
+                error_ind <= 2'b01;
+                rxstate   <=   idle_st;
+             end
+          end
+       end
+       default: rxstate   <=   idle_st;
+    endcase
+   end
+end
+
+
+endmodule

diff --git a/verilog/rtl/uart/src/uart_txfsm.sv b/verilog/rtl/uart/src/uart_txfsm.sv
new file mode 100644
index 0000000..fd8f947
--- /dev/null
+++ b/verilog/rtl/uart/src/uart_txfsm.sv

@@ -0,0 +1,172 @@
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+////  UART TX FSM                                                 ////
+////                                                              ////
+////  This file is part of the YIFive cores project               ////
+////  http://www.opencores.org/cores/yifive/                      ////
+////                                                              ////
+////  Description                                                 ////
+////                                                              ////
+////  To Do:                                                      ////
+////    nothing                                                   ////
+////                                                              ////
+////  Author(s):                                                  ////
+////      - Dinesh Annayya, dinesha@opencores.org                 ////
+////                                                              ////
+////  Revision :                                                  //// 
+////    0.1 - 20th June 2021, Dinesh A                            ////
+////        1. initial version picked from                        ////
+////          http://www.opencores.org/cores/oms8051mini          ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+////                                                              ////
+//// Copyright (C) 2000 Authors and OPENCORES.ORG                 ////
+////                                                              ////
+//// This source file may be used and distributed without         ////
+//// restriction provided that this copyright statement is not    ////
+//// removed from the file and that any derivative work contains  ////
+//// the original copyright notice and the associated disclaimer. ////
+////                                                              ////
+//// This source file is free software; you can redistribute it   ////
+//// and/or modify it under the terms of the GNU Lesser General   ////
+//// Public License as published by the Free Software Foundation; ////
+//// either version 2.1 of the License, or (at your option) any   ////
+//// later version.                                               ////
+////                                                              ////
+//// This source is distributed in the hope that it will be       ////
+//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
+//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
+//// PURPOSE.  See the GNU Lesser General Public License for more ////
+//// details.                                                     ////
+////                                                              ////
+//// You should have received a copy of the GNU Lesser General    ////
+//// Public License along with this source; if not, download it   ////
+//// from http://www.opencores.org/lgpl.shtml                     ////
+////                                                              ////
+//////////////////////////////////////////////////////////////////////
+
+
+module uart_txfsm (
+             reset_n        ,
+             baud_clk_16x   ,
+
+             cfg_tx_enable  ,
+             cfg_stop_bit   ,
+             cfg_pri_mod    ,
+
+       // FIFO control signal
+             fifo_empty     ,
+             fifo_rd        ,
+             fifo_data      ,
+
+          // Line Interface
+             so  
+          );
+
+
+input             reset_n        ; // active low reset signal
+input             baud_clk_16x   ; // baud clock-16x
+
+input             cfg_tx_enable  ; // transmit interface enable
+input             cfg_stop_bit   ; // stop bit 
+                                   // 0 --> 1 stop, 1 --> 2 Stop
+input   [1:0]     cfg_pri_mod    ;// Priority Mode
+                                   // 2'b00 --> None
+                                   // 2'b10 --> Even priority
+                                   // 2'b11 --> Odd priority
+
+//--------------------------------------
+//   FIFO control signal
+//--------------------------------------
+input             fifo_empty     ; // fifo empty
+output            fifo_rd        ; // fifo read, assumed no back to back read
+input  [7:0]      fifo_data      ; // fifo read data
+
+// Line Interface
+output            so             ;  // txd pin
+
+
+reg  [2:0]         txstate       ; // tx state
+reg                so            ; // txd pin
+reg  [7:0]         txdata        ; // local txdata
+reg                fifo_rd       ; // Fifo read enable
+reg  [2:0]         cnt           ; // local data cont
+reg  [3:0]         divcnt        ; // clock div count
+
+parameter idle_st      = 3'b000;
+parameter xfr_data_st  = 3'b001;
+parameter xfr_pri_st   = 3'b010;
+parameter xfr_stop_st1 = 3'b011;
+parameter xfr_stop_st2 = 3'b100;
+
+
+always @(negedge reset_n or posedge baud_clk_16x)
+begin
+   if(reset_n == 1'b0) begin
+      txstate  <= idle_st;
+      so       <= 1'b1;
+      cnt      <= 3'b0;
+      txdata   <= 8'h0;
+      fifo_rd  <= 1'b0;
+      divcnt   <= 4'b0;
+   end
+   else begin
+      divcnt <= divcnt+1;
+      if(divcnt == 4'b0000) begin // Do at once in 16 clock
+         case(txstate)
+          idle_st      : begin
+               if(!fifo_empty && cfg_tx_enable) begin
+                  so       <= 1'b0 ; // Start bit
+                  cnt      <= 3'b0;
+                  fifo_rd  <= 1'b1;
+                  txdata   <= fifo_data;
+                  txstate  <= xfr_data_st;  
+               end
+            end
+
+          xfr_data_st  : begin
+              fifo_rd  <= 1'b0;
+              so   <= txdata[cnt];
+              cnt  <= cnt+1;
+              if(cnt == 7) begin
+                 if(cfg_pri_mod == 2'b00) begin // No Priority
+                    txstate  <= xfr_stop_st1;  
+                 end
+                 else begin
+                    txstate <= xfr_pri_st;  
+                 end
+              end
+           end
+
+          xfr_pri_st   : begin
+               if(cfg_pri_mod == 2'b10)  // even priority
+                   so <= ^txdata;
+               else begin // Odd Priority
+                   so <= ~(^txdata);
+               end
+               txstate  <= xfr_stop_st1;  
+            end
+
+          xfr_stop_st1  : begin // First Stop Bit
+               so <= 1;
+               if(cfg_stop_bit == 0)  // 1 Stop Bit
+                    txstate <= idle_st;
+               else // 2 Stop Bit 
+                  txstate  <= xfr_stop_st2;
+            end
+
+          xfr_stop_st2  : begin // Second Stop Bit
+               so <= 1;
+               txstate <= idle_st;
+            end
+         default: txstate  <= idle_st;
+         endcase
+      end
+     else begin
+        fifo_rd  <= 1'b0;
+     end
+   end
+end
+
+
+endmodule

diff --git a/verilog/rtl/uprj_netlists.v b/verilog/rtl/uprj_netlists.v
index 689eca3..33f2c1f 100644
--- a/verilog/rtl/uprj_netlists.v
+++ b/verilog/rtl/uprj_netlists.v

@@ -31,6 +31,13 @@
     `include "spi_master/src/spim_rx.sv"
     `include "spi_master/src/spim_tx.sv"
 
+    `include "uart/src/uart_core.sv"
+    `include "uart/src/uart_cfg.sv"
+    `include "uart/src/uart_rxfsm.sv"
+    `include "uart/src/uart_txfsm.sv"
+    `include "lib/async_fifo_th.sv"  
+    `include "lib/reset_sync.sv"  
+
      `include "sdram_ctrl/src/top/sdrc_top.v" 
      `include "sdram_ctrl/src/wb2sdrc/wb2sdrc.v" 
      `include "lib/async_fifo.sv"  
@@ -80,4 +87,5 @@
      `include "syntacore/scr1/src/top/scr1_imem_wb.sv"
      `include "syntacore/scr1/src/top/scr1_top_wb.sv"
      `include "lib/sync_fifo.sv"
+
 `endif

diff --git a/verilog/rtl/wb_interconnect/src/wb_interconnect.sv b/verilog/rtl/wb_interconnect/src/wb_interconnect.sv
index 3eb688e..61f7f64 100644
--- a/verilog/rtl/wb_interconnect/src/wb_interconnect.sv
+++ b/verilog/rtl/wb_interconnect/src/wb_interconnect.sv

@@ -20,6 +20,8 @@
 ////    0.2 - 17th June 2021, Dinesh A                            ////
 ////          Stagging FF added at Slave Interface to break       ////
 ////          path                                                ////
+////    0.3 - 21th June 2021, Dinesh A                            ////
+////          slave port 3 added for uart                         ////
 ////                                                              ////
 //////////////////////////////////////////////////////////////////////
 ////                                                              ////
@@ -120,6 +122,18 @@
          output	logic 	        s2_wbd_we_o,
          output	logic 	        s2_wbd_cyc_o,
          output	logic 	        s2_wbd_stb_o
+
+         // Slave 3 Interface
+	 // Uart is 8bit interface 
+         input	logic [7:0]	s3_wbd_dat_i,
+         input	logic 	        s3_wbd_ack_i,
+         input	logic 	        s3_wbd_err_i,
+         output	logic [7:0]	s3_wbd_dat_o,
+         output	logic [7:0]	s3_wbd_adr_o, 
+         output	logic    	s3_wbd_sel_o,
+         output	logic 	        s3_wbd_we_o,
+         output	logic 	        s3_wbd_cyc_o,
+         output	logic 	        s3_wbd_stb_o
 	);
 
 ////////////////////////////////////////////////////////////////////
@@ -161,11 +175,13 @@
 type_wb_wr_intf  s0_wb_wr;
 type_wb_wr_intf  s1_wb_wr;
 type_wb_wr_intf  s2_wb_wr;
+type_wb_wr_intf  s3_wb_wr;
 
 // Slave Read Interface
 type_wb_rd_intf  s0_wb_rd;
 type_wb_rd_intf  s1_wb_rd;
 type_wb_rd_intf  s2_wb_rd;
+type_wb_rd_intf  s3_wb_rd;
 
 
 type_wb_wr_intf  m_bus_wr;  // Multiplexed Master I/F
@@ -179,22 +195,26 @@
 // 0x1000_0000 to 0x1000_00FF  - SPI REGISTER
 // 0x2000_0000 to 0x2FFF_FFFF  - SDRAM
 // 0x3000_0000 to 0x3000_00FF  - GLOBAL REGISTER
+// 0x3000_0000 to 0x3001_00FF  - UART Register
 //-----------------------------
 // 
-wire [3:0] m0_wbd_tid_i     = (m0_wbd_adr_i[31:28] == 4'b0000 ) ? 4'b0000 :
-                              (m0_wbd_adr_i[31:28] == 4'b0001 ) ? 4'b0000 :
-                              (m0_wbd_adr_i[31:28] == 4'b0010 ) ? 4'b0001 :
-                              (m0_wbd_adr_i[31:28] == 4'b0011 ) ? 4'b0010 : 4'b0000;
+wire [3:0] m0_wbd_tid_i     = (m0_wbd_adr_i[31:28] ==  4'b0000 ) ? 4'b0000 :
+                              (m0_wbd_adr_i[31:28] ==  4'b0001 ) ? 4'b0000 :
+                              (m0_wbd_adr_i[31:28] ==  4'b0010 ) ? 4'b0001 :
+                              (m0_wbd_adr_i[31:16] == 16'h3000 ) ? 4'b0010 : 
+                              (m0_wbd_adr_i[31:16] == 16'h3001 ) ? 4'b0011 : 4'b0000; 
 
-wire [3:0] m1_wbd_tid_i     = (m1_wbd_adr_i[31:28] == 4'b0000 ) ? 4'b0000 :
-                              (m1_wbd_adr_i[31:28] == 4'b0001 ) ? 4'b0000 :
-                              (m1_wbd_adr_i[31:28] == 4'b0010 ) ? 4'b0001 : 
-                              (m1_wbd_adr_i[31:28] == 4'b0011 ) ? 4'b0010 : 4'b0000;
+wire [3:0] m1_wbd_tid_i     = (m1_wbd_adr_i[31:28] ==  4'b0000 ) ? 4'b0000 :
+                              (m1_wbd_adr_i[31:28] ==  4'b0001 ) ? 4'b0000 :
+                              (m1_wbd_adr_i[31:28] ==  4'b0010 ) ? 4'b0001 : 
+                              (m1_wbd_adr_i[31:16] == 16'h3000 ) ? 4'b0010 : 
+                              (m1_wbd_adr_i[31:16] == 16'h3001 ) ? 4'b0011 : 4'b0000; 
 
 
 //-------------------------------------------------------------------
 // EXTERNAL MEMORY MAP
 // 0x3000_0000 to 0x3000_00FF -  GLOBAL REGISTER
+// 0x3000_0000 to 0x3001_00FF  - UART Register
 // 0x4000_0000 to 0x4FFF_FFFF -  SPI FLASH MEMORY
 // 0x5000_0000 to 0x5000_00FF -  SPI REGISTER
 // 0x6000_0000 to 0x6FFF_FFFF -  SDRAM
@@ -202,7 +222,8 @@
 wire [3:0] m2_wbd_tid_i       = (m2_wbd_adr_i[31:28] == 4'b0100 ) ? 4'b0000 :
                                 (m2_wbd_adr_i[31:28] == 4'b0101 ) ? 4'b0000 :
                                 (m2_wbd_adr_i[31:28] == 4'b0110 ) ? 4'b0001 :
-                                (m2_wbd_adr_i[31:28] == 4'b0011 ) ? 4'b0010 : 4'b0000;
+                                (m2_wbd_adr_i[31:16] == 16'h3000 ) ? 4'b0010 : 
+                                (m2_wbd_adr_i[31:16] == 16'h3001 ) ? 4'b0011 : 4'b0000; 
 
 //----------------------------------------
 // Master Mapping
@@ -267,6 +288,13 @@
  assign  s2_wbd_we_o  =  s2_wb_wr.wbd_we  ;
  assign  s2_wbd_cyc_o =  s2_wb_wr.wbd_cyc ;
  assign  s2_wbd_stb_o =  s2_wb_wr.wbd_stb ;
+
+ assign  s3_wbd_dat_o =  s3_wb_wr.wbd_dat[7:0] ;
+ assign  s3_wbd_adr_o =  s3_wb_wr.wbd_adr[7:0] ; // Global Reg Need 8 bit
+ assign  s3_wbd_sel_o =  s3_wb_wr.wbd_sel[0] ;
+ assign  s3_wbd_we_o  =  s3_wb_wr.wbd_we  ;
+ assign  s3_wbd_cyc_o =  s3_wb_wr.wbd_cyc ;
+ assign  s3_wbd_stb_o =  s3_wb_wr.wbd_stb ;
  
  assign s0_wb_rd.wbd_dat  = s0_wbd_dat_i ;
  assign s0_wb_rd.wbd_ack  = s0_wbd_ack_i ;
@@ -280,6 +308,9 @@
  assign s2_wb_rd.wbd_ack  = s2_wbd_ack_i ;
  assign s2_wb_rd.wbd_err  = s2_wbd_err_i ;
 
+ assign s3_wb_rd.wbd_dat  = {24'h0,s3_wbd_dat_i} ;
+ assign s3_wb_rd.wbd_ack  = s3_wbd_ack_i ;
+ assign s3_wb_rd.wbd_err  = s3_wbd_err_i ;
 
 //
 // arbitor 
@@ -314,6 +345,7 @@
         3'h0:	   s_bus_rd = s0_wb_rd;
         3'h1:	   s_bus_rd = s1_wb_rd;
         3'h2:	   s_bus_rd = s2_wb_rd;
+        3'h3:	   s_bus_rd = s3_wb_rd;
         default:   s_bus_rd = s0_wb_rd;
      endcase			
 end
@@ -323,6 +355,7 @@
 assign  s0_wb_wr = (s_wbd_tid == 2'b00) ? s_bus_wr : 'h0;
 assign  s1_wb_wr = (s_wbd_tid == 2'b01) ? s_bus_wr : 'h0;
 assign  s2_wb_wr = (s_wbd_tid == 2'b10) ? s_bus_wr : 'h0;
+assign  s3_wb_wr = (s_wbd_tid == 2'b11) ? s_bus_wr : 'h0;
 
 // Connect Slave to Master
 assign  m0_wb_rd = (gnt == 2'b00) ? m_bus_rd : 'h0;