iCE40 bram tests and fixes

6 files changed, 181 insertions, 16 deletions

diff --git a/techlibs/ice40/brams_map.v b/techlibs/ice40/brams_map.v
index 9dbc81e3e..0775aac1f 100644
--- a/techlibs/ice40/brams_map.v
+++ b/techlibs/ice40/brams_map.v
@@ -20,23 +20,23 @@ module \$__ICE40_RAM4K_M0 (CLK2, CLK3, A1ADDR, A1DATA, B1ADDR, B1DATA, B1EN);
 		case ({CLKPOL2, CLKPOL3})
 			2'b00:
 				SB_RAM40_4KNRNW #(.WRITE_MODE(0), .READ_MODE(0)) _TECHMAP_REPLACE_ (
-					.RDATA(A1DATA), .RADDR(A1ADDR_11),               .RCLK(CLK2), .RCLKE(1'b1), .RE(1'b1),
-					.WDATA(B1DATA), .WADDR(B1ADDR_11), .WMASK(B1EN), .WCLK(CLK3), .WCLKE(1'b1), .WE(|B1EN)
+					.RDATA(A1DATA), .RADDR(A1ADDR_11),              .RCLK(CLK2), .RCLKE(1'b1), .RE(1'b1),
+					.WDATA(B1DATA), .WADDR(B1ADDR_11), .MASK(B1EN), .WCLK(CLK3), .WCLKE(1'b1), .WE(|B1EN)
 				);
 			2'b01:
 				SB_RAM40_4KNR #(.WRITE_MODE(0), .READ_MODE(0)) _TECHMAP_REPLACE_ (
-					.RDATA(A1DATA), .RADDR(A1ADDR_11),               .RCLK(CLK2), .RCLKE(1'b1), .RE(1'b1),
-					.WDATA(B1DATA), .WADDR(B1ADDR_11), .WMASK(B1EN), .WCLK(CLK3), .WCLKE(1'b1), .WE(|B1EN)
+					.RDATA(A1DATA), .RADDR(A1ADDR_11),              .RCLK(CLK2), .RCLKE(1'b1), .RE(1'b1),
+					.WDATA(B1DATA), .WADDR(B1ADDR_11), .MASK(B1EN), .WCLK(CLK3), .WCLKE(1'b1), .WE(|B1EN)
 				);
 			2'b10:
 				SB_RAM40_4KNW #(.WRITE_MODE(0), .READ_MODE(0)) _TECHMAP_REPLACE_ (
-					.RDATA(A1DATA), .RADDR(A1ADDR_11),               .RCLK(CLK2), .RCLKE(1'b1), .RE(1'b1),
-					.WDATA(B1DATA), .WADDR(B1ADDR_11), .WMASK(B1EN), .WCLK(CLK3), .WCLKE(1'b1), .WE(|B1EN)
+					.RDATA(A1DATA), .RADDR(A1ADDR_11),              .RCLK(CLK2), .RCLKE(1'b1), .RE(1'b1),
+					.WDATA(B1DATA), .WADDR(B1ADDR_11), .MASK(B1EN), .WCLK(CLK3), .WCLKE(1'b1), .WE(|B1EN)
 				);
 			2'b11:
 				SB_RAM40_4K #(.WRITE_MODE(0), .READ_MODE(0)) _TECHMAP_REPLACE_ (
-					.RDATA(A1DATA), .RADDR(A1ADDR_11),               .RCLK(CLK2), .RCLKE(1'b1), .RE(1'b1),
-					.WDATA(B1DATA), .WADDR(B1ADDR_11), .WMASK(B1EN), .WCLK(CLK3), .WCLKE(1'b1), .WE(|B1EN)
+					.RDATA(A1DATA), .RADDR(A1ADDR_11),              .RCLK(CLK2), .RCLKE(1'b1), .RE(1'b1),
+					.WDATA(B1DATA), .WADDR(B1ADDR_11), .MASK(B1EN), .WCLK(CLK3), .WCLKE(1'b1), .WE(|B1EN)
 				);
 		endcase
 	endgenerate
diff --git a/techlibs/ice40/cells_sim.v b/techlibs/ice40/cells_sim.v
index 4a11e4a9e..4dc011be4 100644
--- a/techlibs/ice40/cells_sim.v
+++ b/techlibs/ice40/cells_sim.v
@@ -305,20 +305,43 @@ module SB_RAM40_4K (
 	always @(posedge WCLK) begin
 		if (WE && WCLKE) begin
 			if (WRITE_MODE == 0) begin
-				for (i=0; i<16; i=i+1)
-					if (MASK[i]) memory[WADDR[7:0]][i] <= WDATA[i];
+				if (MASK[ 0]) memory[WADDR[7:0]][ 0] <= WDATA[ 0];
+				if (MASK[ 1]) memory[WADDR[7:0]][ 1] <= WDATA[ 1];
+				if (MASK[ 2]) memory[WADDR[7:0]][ 2] <= WDATA[ 2];
+				if (MASK[ 3]) memory[WADDR[7:0]][ 3] <= WDATA[ 3];
+				if (MASK[ 4]) memory[WADDR[7:0]][ 4] <= WDATA[ 4];
+				if (MASK[ 5]) memory[WADDR[7:0]][ 5] <= WDATA[ 5];
+				if (MASK[ 6]) memory[WADDR[7:0]][ 6] <= WDATA[ 6];
+				if (MASK[ 7]) memory[WADDR[7:0]][ 7] <= WDATA[ 7];
+				if (MASK[ 8]) memory[WADDR[7:0]][ 8] <= WDATA[ 8];
+				if (MASK[ 9]) memory[WADDR[7:0]][ 9] <= WDATA[ 9];
+				if (MASK[10]) memory[WADDR[7:0]][10] <= WDATA[10];
+				if (MASK[11]) memory[WADDR[7:0]][11] <= WDATA[11];
+				if (MASK[12]) memory[WADDR[7:0]][12] <= WDATA[12];
+				if (MASK[13]) memory[WADDR[7:0]][13] <= WDATA[13];
+				if (MASK[14]) memory[WADDR[7:0]][14] <= WDATA[14];
+				if (MASK[15]) memory[WADDR[7:0]][15] <= WDATA[15];
+				if (MASK[16]) memory[WADDR[7:0]][16] <= WDATA[16];
 			end
 			if (WRITE_MODE == 1) begin
-				for (i=0; i<2; i=i+1)
-					if (WADDR[0] == i) memory[WADDR[8:1]][i*8 +: 8] <= WDATA[i][7:0];
+				if (WADDR[0] == 0) memory[WADDR[8:1]][0*8 +: 8] <= WDATA[7:0];
+				if (WADDR[0] == 1) memory[WADDR[8:1]][1*8 +: 8] <= WDATA[7:0];
 			end
 			if (WRITE_MODE == 2) begin
-				for (i=0; i<4; i=i+1)
-					if (WADDR[1:0] == i) memory[WADDR[9:2]][i*4 +: 4] <= WDATA[i][3:0];
+				if (WADDR[1:0] == 0) memory[WADDR[9:2]][0*4 +: 4] <= WDATA[3:0];
+				if (WADDR[1:0] == 1) memory[WADDR[9:2]][1*4 +: 4] <= WDATA[3:0];
+				if (WADDR[1:0] == 2) memory[WADDR[9:2]][2*4 +: 4] <= WDATA[3:0];
+				if (WADDR[1:0] == 3) memory[WADDR[9:2]][3*4 +: 4] <= WDATA[3:0];
 			end
 			if (WRITE_MODE == 3) begin
-				for (i=0; i<8; i=i+1)
-					if (WADDR[2:0] == i) memory[WADDR[10:3]][i*2 +: 2] <= WDATA[i][1:0];
+				if (WADDR[2:0] == 0) memory[WADDR[10:3]][0*2 +: 2] <= WDATA[1:0];
+				if (WADDR[2:0] == 1) memory[WADDR[10:3]][1*2 +: 2] <= WDATA[1:0];
+				if (WADDR[2:0] == 2) memory[WADDR[10:3]][2*2 +: 2] <= WDATA[1:0];
+				if (WADDR[2:0] == 3) memory[WADDR[10:3]][3*2 +: 2] <= WDATA[1:0];
+				if (WADDR[2:0] == 4) memory[WADDR[10:3]][4*2 +: 2] <= WDATA[1:0];
+				if (WADDR[2:0] == 5) memory[WADDR[10:3]][5*2 +: 2] <= WDATA[1:0];
+				if (WADDR[2:0] == 6) memory[WADDR[10:3]][6*2 +: 2] <= WDATA[1:0];
+				if (WADDR[2:0] == 7) memory[WADDR[10:3]][7*2 +: 2] <= WDATA[1:0];
 			end
 		end
 	end
diff --git a/techlibs/ice40/tests/.gitignore b/techlibs/ice40/tests/.gitignore
index e15bc0fc8..b58f9ad4a 100644
--- a/techlibs/ice40/tests/.gitignore
+++ b/techlibs/ice40/tests/.gitignore
@@ -1 +1,2 @@
 test_ffs_[01][01][01][01][01]_*
+test_bram_[0-9]*
diff --git a/techlibs/ice40/tests/test_bram.sh b/techlibs/ice40/tests/test_bram.sh
new file mode 100644
index 000000000..d24c50bc5
--- /dev/null
+++ b/techlibs/ice40/tests/test_bram.sh
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+set -ex
+
+for abits in 7 8 9 10 11 12; do
+for dbits in 2 4 8 16 24 32; do
+	id="test_bram_${abits}_${dbits}"
+	sed -e "s/ABITS = ./ABITS = $abits/g; s/DBITS = ./DBITS = $dbits/g;" < test_bram.v > ${id}.v
+	sed -e "s/ABITS = ./ABITS = $abits/g; s/DBITS = ./DBITS = $dbits/g;" < test_bram_tb.v > ${id}_tb.v
+	../../../yosys -ql ${id}_syn.log -p "synth_ice40" -o ${id}_syn.v ${id}.v
+	iverilog -s bram_tb -o ${id}_tb ${id}_syn.v ${id}_tb.v /opt/lscc/iCEcube2.2014.08/verilog/sb_ice_syn.v
+	# iverilog -s bram_tb -o ${id}_tb ${id}_syn.v ${id}_tb.v ../cells_sim.v
+	./${id}_tb > ${id}_tb.txt
+	if grep ERROR ${id}_tb.txt; then false; fi
+done; done
+echo OK
+
diff --git a/techlibs/ice40/tests/test_bram.v b/techlibs/ice40/tests/test_bram.v
new file mode 100644
index 000000000..d26df7572
--- /dev/null
+++ b/techlibs/ice40/tests/test_bram.v
@@ -0,0 +1,19 @@
+module bram #(
+	parameter ABITS = 8, DBITS = 8
+) (
+	input clk,
+
+	input [ABITS-1:0] WR_ADDR,
+	input [DBITS-1:0] WR_DATA,
+	input WR_EN,
+
+	input [ABITS-1:0] RD_ADDR,
+	output reg [DBITS-1:0] RD_DATA
+);
+	reg [DBITS-1:0] memory [0:2**ABITS-1];
+
+	always @(posedge clk) begin
+		if (WR_EN) memory[WR_ADDR] <= WR_DATA;
+		RD_DATA <= memory[RD_ADDR];
+	end
+endmodule
diff --git a/techlibs/ice40/tests/test_bram_tb.v b/techlibs/ice40/tests/test_bram_tb.v
new file mode 100644
index 000000000..b0ac0402a
--- /dev/null
+++ b/techlibs/ice40/tests/test_bram_tb.v
@@ -0,0 +1,105 @@
+module bram_tb #(
+	parameter ABITS = 8, DBITS = 8
+);
+	reg clk;
+	reg [ABITS-1:0] WR_ADDR;
+	reg [DBITS-1:0] WR_DATA;
+	reg WR_EN;
+	reg [ABITS-1:0] RD_ADDR;
+	wire [DBITS-1:0] RD_DATA;
+
+	bram uut  (
+		.clk    (clk    ),
+		.WR_ADDR(WR_ADDR),
+		.WR_DATA(WR_DATA),
+		.WR_EN  (WR_EN  ),
+		.RD_ADDR(RD_ADDR),
+		.RD_DATA(RD_DATA)
+	);
+
+	reg [63:0] xorshift64_state = 64'd88172645463325252 ^ (ABITS << 24) ^ (DBITS << 16);
+
+	task xorshift64_next;
+		begin
+		// see page 4 of Marsaglia, George (July 2003). "Xorshift RNGs". Journal of Statistical Software 8 (14).
+		xorshift64_state = xorshift64_state ^ (xorshift64_state << 13);
+		xorshift64_state = xorshift64_state ^ (xorshift64_state >>  7);
+		xorshift64_state = xorshift64_state ^ (xorshift64_state << 17);
+		end
+	endtask
+
+	reg [ABITS-1:0] randaddr1;
+	reg [ABITS-1:0] randaddr2;
+	reg [ABITS-1:0] randaddr3;
+
+	function [31:0] getaddr(input [3:0] n);
+		begin
+			case (n)
+				0: getaddr = 0;
+				1: getaddr = 2**ABITS-1;
+				2: getaddr = 'b101 << (ABITS / 3);
+				3: getaddr = 'b101 << (2*ABITS / 3);
+				4: getaddr = 'b11011 << (ABITS / 4);
+				5: getaddr = 'b11011 << (2*ABITS / 4);
+				6: getaddr = 'b11011 << (3*ABITS / 4);
+				7: getaddr = randaddr1;
+				8: getaddr = randaddr2;
+				9: getaddr = randaddr3;
+				default: begin
+					getaddr = 1 << (2*n-16);
+					if (!getaddr) getaddr = xorshift64_state;
+				end
+			endcase
+		end
+	endfunction
+
+	reg [DBITS-1:0] memory [0:2**ABITS-1];
+	reg [DBITS-1:0] expected_rd, expected_rd_masked;
+
+	event error;
+	integer i, j;
+
+	initial begin
+		// $dumpfile("testbench.vcd");
+		// $dumpvars(0, bram_tb);
+
+		xorshift64_next;
+		xorshift64_next;
+		xorshift64_next;
+		xorshift64_next;
+
+		randaddr1 = xorshift64_state;
+		xorshift64_next;
+
+		randaddr2 = xorshift64_state;
+		xorshift64_next;
+
+		randaddr3 = xorshift64_state;
+		xorshift64_next;
+
+		clk <= 0;
+		for (i = 0; i < 512; i = i+1) begin
+			WR_DATA <= xorshift64_state;
+			xorshift64_next;
+
+			WR_ADDR <= getaddr(i < 256 ? i[7:4] : xorshift64_state[63:60]);
+			xorshift64_next;
+
+			RD_ADDR <= getaddr(i < 256 ? i[3:0] : xorshift64_state[59:56]);
+			WR_EN <= xorshift64_state[55];
+			xorshift64_next;
+
+			#1; clk <= 1;
+			#1; clk <= 0;
+
+			expected_rd = memory[RD_ADDR];
+			if (WR_EN) memory[WR_ADDR] = WR_DATA;
+
+			for (j = 0; j < DBITS; j = j+1)
+				expected_rd_masked[j] = expected_rd[j] !== 1'bx ? expected_rd[j] : RD_DATA[j];
+
+			$display("#OUT# %3d | WA=%x WD=%x WE=%x | RA=%x RD=%x (%x) | %s", i, WR_ADDR, WR_DATA, WR_EN, RD_ADDR, RD_DATA, expected_rd, expected_rd_masked === RD_DATA ? "ok" : "ERROR");
+			if (expected_rd_masked !== RD_DATA) begin -> error; end
+		end
+	end
+endmodule