/*
 *  StriVe - A full example SoC using PicoRV32 in SkyWater s8
 *
 *  Copyright (C) 2017  Clifford Wolf <clifford@clifford.at>
 *  Copyright (C) 2018  Tim Edwards <tim@efabless.com>
 *
 *  Permission to use, copy, modify, and/or distribute this software for any
 *  purpose with or without fee is hereby granted, provided that the above
 *  copyright notice and this permission notice appear in all copies.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

`timescale 1 ns / 1 ps

`include "caravel.v"
`include "spiflash.v"
`include "tbuart.v"

module uart_tb;
	reg clock;
	reg RSTB;
	reg power1, power2;

	wire gpio;
	wire flash_csb;
	wire flash_clk;
	wire flash_io0;
	wire flash_io1;
	wire [37:0] mprj_io;
	wire [15:0] checkbits;
	wire uart_tx;
	wire SDO;

	assign checkbits = mprj_io[31:16];
	assign uart_tx = mprj_io[6];

	always #12.5 clock <= (clock === 1'b0);

	initial begin
		clock = 0;
	end

	initial begin
		$dumpfile("uart.vcd");
		$dumpvars(0, uart_tb);

		$display("Wait for UART o/p");
		repeat (150) begin
			repeat (10000) @(posedge clock);
			// Diagnostic. . . interrupts output pattern.
		end
		$finish;
	end

	initial begin
		RSTB <= 1'b0;
		#1000;
		RSTB <= 1'b1;	    // Release reset
		#2000;
	end

	initial begin		// Power-up sequence
		power1 <= 1'b0;
		power2 <= 1'b0;
		#200;
		power1 <= 1'b1;
		#200;
		power2 <= 1'b1;
	end

	always @(checkbits) begin
		if(checkbits == 16'hA000) begin
			$display("UART Test started");
		end
		else if(checkbits == 16'hAB00) begin
			$display("UART Test passed");
			$finish;
		end
	end

	wire VDD3V3;
	wire VDD1V8;
	wire VSS;

	assign VDD3V3 = power1;
	assign VDD1V8 = power2;
	assign VSS = 1'b0;

	caravel uut (
		.vddio	  (VDD3V3),
		.vssio	  (VSS),
		.vdda	  (VDD3V3),
		.vssa	  (VSS),
		.vccd	  (VDD1V8),
		.vssd	  (VSS),
		.vdda1    (VDD3V3),
		.vdda2    (VDD3V3),
		.vssa1	  (VSS),
		.vssa2	  (VSS),
		.vccd1	  (VDD1V8),
		.vccd2	  (VDD1V8),
		.vssd1	  (VSS),
		.vssd2	  (VSS),
		.clock	  (clock),
		.gpio     (gpio),
		.mprj_io  (mprj_io),
		.flash_csb(flash_csb),
		.flash_clk(flash_clk),
		.flash_io0(flash_io0),
		.flash_io1(flash_io1),
		.resetb	  (RSTB)
	);

	spiflash #(
		.FILENAME("uart.hex")
	) spiflash (
		.csb(flash_csb),
		.clk(flash_clk),
		.io0(flash_io0),
		.io1(flash_io1),
		.io2(),			// not used
		.io3()			// not used
	);

	// Testbench UART
	tbuart tbuart (
		.ser_rx(uart_tx)
	);
		
endmodule