Fix stalling

Author: Parham Farrokhi

Sec_8/ForwardUnit.v

@@ -5,7 +5,8 @@ module ForwardUnit
 		WB_En1,
 		WB_En2,
 		mem_W_En,
-		MEM_R_En,
+		mem_R_En1,
+		mem_R_En2,
 		Is_Imm,
 		src1,
 		src2,
@@ -19,14 +20,16 @@ module ForwardUnit
 		memOut,
 		shouldForward1,
 		shouldForward2,
+		loadForwardStall
 	);
 
 	// define input and output ports
 	input			WB_En1;
 	input			WB_En2;
 	input			Is_Imm;
 	input			mem_W_En;
-	input			mem_R_En;
+	input			mem_R_En1;
+	input			mem_R_En2;
 	input	[1:0]	BR_Type;
 	input	[4:0]	src1;
 	input	[4:0]	src2;
@@ -47,8 +50,12 @@ module ForwardUnit
 	wire        shouldForward2FromExe;
 	wire        shouldForward1FromMem;
 	wire        shouldForward2FromMem;
-	wire		shouldForwardMemWriteFromExe;
-	wire		shouldForwardMemWriteFromMem;
+	wire				shouldForwardMemWriteFromExe;
+	wire				shouldForwardMemWriteFromMem;
+	wire 				shouldForward1FromMemLoadExe;  // depends on ld result
+	wire 				shouldForward2FromMemLoadExe;
+	wire 				shouldForward1FromMemLoadMem;
+	wire 				shouldForward2FromMemLoadMem;
 	reg	[31:0]	srcOut1;
 	reg	[31:0]	srcOut2;
 	reg	[31:0]	memOut;
@@ -68,7 +75,14 @@ module ForwardUnit
   assign shouldForward1 = shouldForward1FromExe | shouldForward1FromMem;
   assign shouldForward2 = shouldForward2FromExe | shouldForward2FromMem;
 
-	assign loadForwardStall = !( src2 ^ dest1 ) & WB_En1 & mem_R_En & |dest1;
+	// assign shouldForward1FromMemLoadExe = !( src1 ^ dest1 ) & mem_R_En1 & |dest1;
+	// assign shouldForward2FromMemLoadExe = !( src2 ^ dest1 ) & mem_R_En1 & |dest1;
+	assign shouldForward1FromMemLoadMem = !( src1 ^ dest2 ) & mem_R_En2 & |dest2;
+	assign shouldForward2FromMemLoadMem = !( src2 ^ dest2 ) & mem_R_En2 & |dest2;
+
+	assign loadForwardStall =
+		// (shouldForward1FromMemLoadExe | shouldForward2FromMemLoadExe) |
+		(shouldForward1FromMemLoadMem | shouldForward2FromMemLoadMem);
 	// build module
 	always @(*)
 	begin

Sec_8/MIPS.v

@@ -201,7 +201,8 @@ module MIPS
       .WB_En1(WB_En32),
       .WB_En2(WB_En42),
 			.mem_W_En(MEM_W_En22),
-			.MEM_R_En(MEM_R_En22),
+			.mem_R_En1(MEM_R_En32),
+			.mem_R_En2(MEM_R_En42),
       .Is_Imm(Is_Imm2),
       .src1(src12),
       .src2(src22),