`default_nettype none
/*
 *  Copyright (C) 2017  Clifford Wolf <clifford@clifford.at>
 *  Copyright (C) 2018  Tim Edwards <tim@efabless.com>
 *  Copyright (C) 2020  Anton Blanchard <anton@linux.ibm.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 "uprj_netlists.v"
`include "caravel_netlists.v"
`include "spiflash.v"

module minimal;
	reg clock;
	reg RSTB;
	reg microwatt_reset;
	reg CSB;
	reg power1, power2;
	reg power3, power4;

	wire gpio;
	wire [37:0] mprj_io;
	wire [15:0] checkbits;
	wire user_flash_csb;
	wire user_flash_clk;
	inout user_flash_io0;
	inout user_flash_io1;

	assign mprj_io[7] = microwatt_reset;

	assign mprj_io[35] = 1'b1; // Boot from flash

	assign user_flash_csb = mprj_io[8];
	assign user_flash_clk = mprj_io[9];
	assign user_flash_io0 = mprj_io[10];
	assign mprj_io[11] = user_flash_io1;

	assign checkbits = mprj_io[31:16];

	assign mprj_io[3] = (CSB == 1'b1) ? 1'b1 : 1'bz;

	// tie uart RX high
	assign mprj_io[5] = 1;

	// tie JTAG inputs low
	assign mprj_io[15:13] = 0;

	// 100 MHz clock
	always #5 clock <= (clock === 1'b0);

	initial begin
		clock = 0;
	end

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

		$display("Microwatt minimal test");

		// Set the timeout at around 10x what the test should finish
		// in
		repeat (200000) begin
			@(posedge clock);
		end

		$display("Timeout, test failed");
		$fatal;
	end

	initial begin
		RSTB <= 1'b0;
		CSB  <= 1'b1;		// Force CSB high
		microwatt_reset <= 1'b1;
		#2000;
		// Keep the management engine in reset
		//RSTB <= 1'b1;
		//#500;
		microwatt_reset <= 1'b0;
	end

	initial begin		// Power-up sequence
		power1 <= 1'b0;
		power2 <= 1'b0;
		power3 <= 1'b0;
		power4 <= 1'b0;
		#100;
		power1 <= 1'b1;
		#100;
		power2 <= 1'b1;
		// simple_por simulates the GPIO POR reset circuit as a 500 ns
		// delay. We want microwatt to power on after this, so wait
		// 1000 ns.
		#1000;
		power3 <= 1'b1;
		#100;
		power4 <= 1'b1;
	end

	initial begin
		wait(checkbits == 16'h00d5)
		$display("Microwatt alive!");

		$finish;
	end

	wire VDD3V3 = power1;
	wire VDD1V8 = power2;
	wire USER_VDD3V3 = power3;
	wire USER_VDD1V8 = power4;
	wire VSS = 1'b0;

	caravel uut (
		.vddio	  (VDD3V3),
		.vddio_2  (VDD3V3),
		.vssio	  (VSS),
		.vssio_2  (VSS),
		.vdda	  (VDD3V3),
		.vssa	  (VSS),
		.vccd	  (VDD1V8),
		.vssd	  (VSS),
		.vdda1    (USER_VDD3V3),
		.vdda1_2  (USER_VDD3V3),
		.vdda2    (USER_VDD3V3),
		.vssa1	  (VSS),
		.vssa1_2  (VSS),
		.vssa2	  (VSS),
		.vccd1	  (USER_VDD1V8),
		.vccd2	  (USER_VDD1V8),
		.vssd1	  (VSS),
		.vssd2	  (VSS),
		.clock	  (clock),
		.gpio     (gpio),
		.mprj_io  (mprj_io),
		.resetb	  (RSTB)
	);

	spiflash #(
		.FILENAME("microwatt.hex")
	) spiflash_microwatt (
		.csb(user_flash_csb),
		.clk(user_flash_clk),
		.io0(user_flash_io0),
		.io1(user_flash_io1),
		.io2(),			// not used
		.io3()			// not used
	);

endmodule
`default_nettype wire