From 694b3fbb6fcfd706ffdb55528168dc891e0d5243 Mon Sep 17 00:00:00 2001
From: Ross Thompson <ross1728@gmail.com>
Date: Mon, 25 Oct 2021 15:33:33 -0500
Subject: [PATCH] Possible fix for critical path timing in caches.

---
 wally-pipelined/src/cache/sram1rw.sv | 42 +++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/wally-pipelined/src/cache/sram1rw.sv b/wally-pipelined/src/cache/sram1rw.sv
index 835e7061f..e98b18f31 100644
--- a/wally-pipelined/src/cache/sram1rw.sv
+++ b/wally-pipelined/src/cache/sram1rw.sv
@@ -1,6 +1,7 @@
+/* -----\/----- EXCLUDED -----\/-----
 // Depth is number of bits in one "word" of the memory, width is number of such words
 
-/* verilator lint_off ASSIGNDLY */
+/-* verilator lint_off ASSIGNDLY *-/
 
 module sram1rw #(parameter DEPTH=128, WIDTH=256) (
     input logic 		    clk,
@@ -29,5 +30,44 @@ module sram1rw #(parameter DEPTH=128, WIDTH=256) (
   
 endmodule
 
+/-* verilator lint_on ASSIGNDLY *-/
+ -----/\----- EXCLUDED -----/\----- */
+
+
+// Depth is number of bits in one "word" of the memory, width is number of such words
+
+/* verilator lint_off ASSIGNDLY */
+
+module sram1rw #(parameter DEPTH=128, WIDTH=256) (
+    input logic 		    clk,
+    // port 1 is read only
+    input logic [$clog2(WIDTH)-1:0] Addr,
+    output logic [DEPTH-1:0] 	    ReadData,
+  
+    // port 2 is write only
+    input logic [DEPTH-1:0] 	    WriteData,
+    input logic 		    WriteEnable
+);
+
+    logic [WIDTH-1:0][DEPTH-1:0] StoredData;
+    logic [$clog2(WIDTH)-1:0] 	 AddrD;
+    logic [WIDTH-1:0] 		 WriteDataD;
+    logic 			 WriteEnableD;
+  
+
+    always_ff @(posedge clk) begin
+      AddrD <= Addr;
+      WriteDataD <= WriteData;
+      WriteEnableD <= WriteEnable;
+        if (WriteEnableD) begin
+            StoredData[AddrD] <= #1 WriteDataD;
+        end
+    end
+
+      
+  assign ReadData = StoredData[AddrD];
+  
+endmodule
+
 /* verilator lint_on ASSIGNDLY */