YosysHQ/nextpnr#148

1 files changed, 40 insertions, 0 deletions

diff --git a/ice40/regressions/issue0148/hdl/simram.sv b/ice40/regressions/issue0148/hdl/simram.sv
new file mode 100644
index 0000000..fc87f07
--- /dev/null
+++ b/ice40/regressions/issue0148/hdl/simram.sv
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+// Copyright 2015, Brian Swetland <swetland@frotz.net>
+// Licensed under the Apache License, Version 2.0.
+
+`timescale 1ns / 1ps
+
+import "DPI-C" function void dpi_mem_write(int addr, int data);
+import "DPI-C" function void dpi_mem_read(int addr, output int data);
+
+module simram(
+	input clk,
+	input [15:0]waddr,
+	input [15:0]wdata,
+	input we,
+	input [15:0]raddr,
+	output reg [15:0]rdata,
+	input re
+	);
+
+	wire [31:0]rawdata;
+	wire [31:0]junk;
+
+	// hack: this should be posedge but if we do that
+	// then the dpi_mem_write() happens too early
+	always @(negedge clk) begin
+		if (we) begin
+			$display(":WRI %08x %08x", waddr, wdata);
+			dpi_mem_write({16'd0, waddr}, {16'd0, wdata});
+		end
+	end
+	always @(posedge clk) begin
+		if (re) begin
+			dpi_mem_read({16'd0, raddr}, rawdata);
+			rdata <= rawdata[15:0];
+		end else begin
+			//junk = $random();
+			//rdata <= junk[15:0];
+			rdata <= 16'hEEEE;
+		end
+	end
+endmodule