diff --git a/techlibs/ice40/brams_map.v b/techlibs/ice40/brams_map.v
index 0775aac1f..d022def7f 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), .MASK(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), .MASK(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), .MASK(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), .MASK(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
@@ -67,9 +67,26 @@ module \$__ICE40_RAM4K_M123 (CLK2, CLK3, A1ADDR, A1DATA, B1ADDR, B1DATA, B1EN);
 	wire [10:0] A1ADDR_11 = A1ADDR;
 	wire [10:0] B1ADDR_11 = B1ADDR;
 
-	wire [15:0] A1DATA_16;
-	wire [15:0] B1DATA_16 = B1DATA;
-	assign A1DATA = A1DATA_16;
+	wire [15:0] A1DATA_16, B1DATA_16;
+
+	generate
+		if (MODE == 1) begin
+			assign A1DATA = {A1DATA_16[14], A1DATA_16[12], A1DATA_16[10], A1DATA_16[ 8],
+			                 A1DATA_16[ 6], A1DATA_16[ 4], A1DATA_16[ 2], A1DATA_16[ 0]};
+			assign B1DATA_16 = {B1DATA[7], B1DATA[7], B1DATA[6], B1DATA[6], B1DATA[5], B1DATA[5], B1DATA[4], B1DATA[4],
+			                    B1DATA[3], B1DATA[3], B1DATA[2], B1DATA[2], B1DATA[1], B1DATA[1], B1DATA[0], B1DATA[0]};
+		end
+		if (MODE == 2) begin
+			assign A1DATA = {A1DATA_16[13], A1DATA_16[9], A1DATA_16[5], A1DATA_16[1]};
+			assign B1DATA_16 = {B1DATA[3], B1DATA[3], B1DATA[3], B1DATA[3], B1DATA[2], B1DATA[2], B1DATA[2], B1DATA[2],
+			                    B1DATA[1], B1DATA[1], B1DATA[1], B1DATA[1], B1DATA[0], B1DATA[0], B1DATA[0], B1DATA[0]};
+		end
+		if (MODE == 3) begin
+			assign A1DATA = {A1DATA_16[11], A1DATA_16[3]};
+			assign B1DATA_16 = {B1DATA[1], B1DATA[1], B1DATA[1], B1DATA[1], B1DATA[1], B1DATA[1], B1DATA[1], B1DATA[1],
+			                    B1DATA[0], B1DATA[0], B1DATA[0], B1DATA[0], B1DATA[0], B1DATA[0], B1DATA[0], B1DATA[0]};
+		end
+	endgenerate
 
 	generate
 		case ({CLKPOL2, CLKPOL3})
diff --git a/techlibs/ice40/tests/test_bram_tb.v b/techlibs/ice40/tests/test_bram_tb.v
index b0ac0402a..5d9f92228 100644
--- a/techlibs/ice40/tests/test_bram_tb.v
+++ b/techlibs/ice40/tests/test_bram_tb.v
@@ -79,14 +79,14 @@ module bram_tb #(
 
 		clk <= 0;
 		for (i = 0; i < 512; i = i+1) begin
-			WR_DATA <= xorshift64_state;
+			WR_DATA = xorshift64_state;
 			xorshift64_next;
 
-			WR_ADDR <= getaddr(i < 256 ? i[7:4] : xorshift64_state[63:60]);
+			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];
+			RD_ADDR = getaddr(i < 256 ? i[3:0] : xorshift64_state[59:56]);
+			WR_EN = xorshift64_state[55] && (WR_ADDR != RD_ADDR);
 			xorshift64_next;
 
 			#1; clk <= 1;
@@ -98,7 +98,9 @@ module bram_tb #(
 			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");
+			$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