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// SPDX-FileCopyrightText: 2020 Astria Nur Irfansyah
//
// 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
`default_nettype none
/*
*-------------------------------------------------------------
*
* top_astria.v
* (adapted from user_proj_example from caravel repo)
*
* Description:
* Test circuits containing:
* 1. Array of synthesized analog comparators for stochastic ADC (3 banks)
* 2. Support circuits
* 3. LIF Neuron (not implemented in this version)
*
* (1) Analog Comparator Bank 1, contains 32 comparators
* Name : comp32
* Input : vcomp32_a, vcomp32_b --> GPIO analogio (24,25) (offset from dig)
* Output: [31:0] comp32out --> GPIO [31:0],
* Logic Analyzer (LA) -> [31:0] la_data_out
* rdata / wbs_dat_o
* (2) Analog Comparator Bank 2 & 3, contains 256 comparators each
* Name : comp256_1, comp256_2
* Input : [1:0] vcomp256_a, [1:0] vcomp256_b --> GPIO analogio (26,27,28,29)
* Output: [1:0] comp256out --> GPIO (37,38),
* Logic Analyzer (LA) -> (32,33)
*
*-------------------------------------------------------------
*/
module top_astria #(
parameter BITS = 32
)(
`ifdef USE_POWER_PINS
inout vdda1, // User area 1 3.3V supply
inout vdda2, // User area 2 3.3V supply
inout vssa1, // User area 1 analog ground
inout vssa2, // User area 2 analog ground
inout vccd1, // User area 1 1.8V supply
inout vccd2, // User area 2 1.8v supply
inout vssd1, // User area 1 digital ground
inout vssd2, // User area 2 digital ground
`endif
// Wishbone Slave ports (WB MI A)
input wb_clk_i,
input wb_rst_i,
input wbs_stb_i,
input wbs_cyc_i,
input wbs_we_i,
input [3:0] wbs_sel_i,
input [31:0] wbs_dat_i,
input [31:0] wbs_adr_i,
output wbs_ack_o,
output [31:0] wbs_dat_o,
// Logic Analyzer Signals
input [127:0] la_data_in,
output [127:0] la_data_out,
input [127:0] la_oen,
// IOs
input [`MPRJ_IO_PADS-1:0] io_in,
output [`MPRJ_IO_PADS-1:0] io_out,
output [`MPRJ_IO_PADS-1:0] io_oeb,
// Analog (direct connection to GPIO pad---use with caution)
// Note that analog I/O is not available on the 7 lowest-numbered
// GPIO pads, and so the analog_io indexing is offset from the
// GPIO indexing by 7.
inout [`MPRJ_IO_PADS-8:0] analog_io
);
wire clk;
wire rst;
wire [`MPRJ_IO_PADS-1:0] io_in;
wire [`MPRJ_IO_PADS-1:0] io_out;
wire [`MPRJ_IO_PADS-1:0] io_oeb;
wire [31:0] rdata;
wire [31:0] wdata;
wire [BITS-1:0] comp32out;
wire comp256out;
wire valid;
wire [3:0] wstrb;
wire [31:0] la_write;
// WB MI A
assign valid = wbs_cyc_i && wbs_stb_i;
assign wstrb = wbs_sel_i & {4{wbs_we_i}};
assign wbs_dat_o = rdata;
assign wdata = wbs_dat_i;
// Comparator wires
//wire [1:0] comp256out;
// IO
assign io_out = {comp256out,comp32out[30:0]}; // cut 1 out from comp32
// assign io_out = {comp256out,comp32out[29:0]}; // cut 2 out from comp32
// assign io_out = {comp32out[31:0]}; // cut 2 out from comp32
assign io_oeb = {(`MPRJ_IO_PADS-1){rst}};
// LA
// assign la_data_out = {{(127-BITS-2){1'b0}},comp256out,comp32out};
assign la_data_out = {{(127-BITS){1'b0}},comp32out};
// Assuming LA probes [63:32] are for controlling the count register
assign la_write = ~la_oen[65:34] & ~{BITS{valid}};
// Assuming LA probes [67:66] are for controlling the clk & reset
assign clk = (~la_oen[66]) ? la_data_in[66]: wb_clk_i;
assign rst = (~la_oen[67]) ? la_data_in[67]: wb_rst_i;
stoch_adc_comp #(
.BITS(BITS),
.COMP_TOTAL(128)
) stoch_adc_comp(
.clk(clk),
.reset(rst),
.ready(wbs_ack_o),
.valid(valid),
.rdata(rdata),
.wdata(wbs_dat_i),
.wstrb(wstrb),
.la_write(la_write),
.la_input(la_data_in[65:34]),
.vcomp32_a(analog_io[24]),
.vcomp32_b(analog_io[25]),
.vcomp256_a(analog_io[26]),
.vcomp256_b(analog_io[28]),
// .vcomp256_a(analog_io[27:26]),
// .vcomp256_b(analog_io[29:28]),
.comp32out(comp32out),
.comp256out(comp256out)
);
endmodule
module stoch_adc_comp #(
parameter BITS = 32,
parameter COMP_TOTAL = 128
)(
input clk,
input reset,
input valid,
input [3:0] wstrb,
input [BITS-1:0] wdata,
input [BITS-1:0] la_write,
input [BITS-1:0] la_input,
inout vcomp32_a,
inout vcomp32_b,
inout vcomp256_a,
inout vcomp256_b,
// input [1:0] vcomp256_a,
// input [1:0] vcomp256_b,
output ready,
output [BITS-1:0] rdata,
output [BITS-1:0] comp32out,
output comp256out
// output [1:0] comp256out
);
reg ready;
reg [BITS-1:0] rdata;
// Comparator output registers
reg [BITS-1:0] comp32out; // Bank 1
reg [COMP_TOTAL-1:0] comp256out1_reg; // Bank 2
// reg [COMP_TOTAL-1:0] comp256out2_reg; // Bank 3
wire [COMP_TOTAL-1:0] comp256out1_wire; // Bank 2
// wire [COMP_TOTAL-1:0] comp256out2_wire; // Bank 3
// Comparator output shift registers
reg [COMP_TOTAL-1:0] comp256out1_sreg; // Bank 2
// reg [COMP_TOTAL-1:0] comp256out2_sreg; // Bank 3
reg [6:0] counter_comp_sreg; // don't forget to adjust according to COMP_TOTAL
// Take output from LSB of comp output shift reg
// assign comp256out = comp256out1_wire[0];
assign comp256out = comp256out1_sreg[0];
// assign comp256out[0] = comp256out1_sreg[0];
// assign comp256out[1] = comp256out2_sreg[0];
// Dummy reg to take write operation from wishbone
// Maybe useful later.
reg [31:0] dummy;
always @(posedge clk) begin
if (reset) begin
counter_comp_sreg <= 0;
ready <= 0;
end else begin
ready <= 1'b0;
if (~|la_write) begin
// shift outputs
counter_comp_sreg <= counter_comp_sreg + 1;
comp256out1_sreg <= {comp256out1_sreg[0],comp256out1_sreg[COMP_TOTAL-1:1]};
// comp256out2_sreg <= {{1'b0},comp256out2_sreg[31:1]};
end
if (valid && !ready) begin
ready <= 1'b1;
rdata <= comp32out;
if (wstrb[0]) dummy[7:0] <= wdata[7:0];
if (wstrb[1]) dummy[15:8] <= wdata[15:8];
if (wstrb[2]) dummy[23:16] <= wdata[23:16];
if (wstrb[3]) dummy[31:24] <= wdata[31:24];
end
if (counter_comp_sreg == 0) begin
comp256out1_sreg <= comp256out1_reg;
// comp256out2_sreg <= comp256out2_reg;
end
end
end
/*
genvar i;
generate
for(i=0; i<BITS; i=i+1) begin
always @(posedge clk) begin
if (la_write[i]) count[i] <= la_input[i];
end
end
endgenerate
*/
genvar j;
generate
for(j=0; j<32; j=j+1) begin
synthcomp comp32(.clk(clk), .v_a(vcomp32_a), .v_b(vcomp32_b), .comp_out(comp32out[j]));
end
endgenerate
genvar k;
generate
for(k=0; k<COMP_TOTAL; k=k+1) begin
synthcomp comp256_1(.clk(clk), .v_a(vcomp256_a), .v_b(vcomp256_b), .comp_out(comp256out1_wire[k]));
end
endgenerate
/*
genvar k;
generate
for(k=0; k<COMP_TOTAL; k=k+1) begin
synthcomp comp256_1(clk, vcomp256_a[0], vcomp256_b[0], comp256out1_wire[k]);
end
endgenerate
genvar l;
generate
for(l=0; l<COMP_TOTAL; l=l+1) begin
synthcomp comp256_2(clk, vcomp256_a[1], vcomp256_b[1], comp256out2_wire[l]);
end
endgenerate
always @(posedge clk) begin
comp256out1_reg <= comp256out1_wire;
comp256out2_reg <= comp256out2_wire;
end
*/
endmodule
/* ----------------------
Synthesizable analog clocked comparator based on Sky130 NOR4 cells
Similar principle to NAND3 based design reported in:
[1] S. Weaver, B. Hershberg, and U.K. Moon,
"Digitally Synthesized Stochastic Flash ADC Using Only Standard Digital Cells,"
IEEE Trans. Circuits Syst. I, doi: 10.1109/TCSI.2013.2268571
-------------------------
*/
module synthcomp (
input clk,
inout v_a,
inout v_b,
output reg comp_out);
wire qa, qb, qx, qcomp_out;
sky130_fd_sc_hd__nor4_1 X_NOR1 (
// `ifdef USE_POWER_PINS
// .VPWR(VPWR),
// .VGND(VGND),
// .VPB(VPWR),
// .VNB(VGND),
// `endif,
.Y(qa), .A(v_a), .B(qb), .C(qb), .D(clk));
sky130_fd_sc_hd__nor4_1 X_NOR2 (
.Y(qb), .A(v_b), .B(qa), .C(qa), .D(clk));
sky130_fd_sc_hd__nor4_1 X_NOR3 (
.Y(qcomp_out), .A(qa), .B(qa), .C(qx), .D(qx));
sky130_fd_sc_hd__nor4_1 X_NOR4 (
.Y(qx), .A(qb), .B(qb), .C(qcomp_out), .D(qcomp_out));
always @(posedge clk)
begin
comp_out <= qcomp_out;
end
endmodule
`default_nettype wire