Merge branch 'main' of https://github.com/supleed2/AM04_CPU into main

inputs/j/j-2.ref.txt

@@ -1 +1 @@
-3
+2

rtl/mips_cpu_harvard.v

@@ -30,12 +30,13 @@ logic[31:0] out_pc_out, out_ALURes, out_readdata1, out_readdata2, in_B, in_write
 logic[4:0]  in_readreg1, in_readreg2, in_writereg, out_shamt, out_ALUOp;
 logic[5:0]  in_opcode;
 logic out_ALUCond, out_RegWrite, out_MemWrite, out_MemRead, out_SpcRegWriteEn;
-logic[1:0] out_RegDst, out_PC, out_ALUSrc;
+logic[1:0] out_RegDst, out_PC, out_ALUSrc, ALURes_offset;
 logic[2:0] out_MemtoReg;
 
 assign in_readreg1 = instr_readdata[25:21];
 assign in_readreg2 = instr_readdata[20:16];
 assign in_opcode   = instr_readdata[31:26];
+assign ALURes_offset = out_ALURes[1:0];
 
 always @(*) begin
     //Picking what register should be written to.
@@ -116,6 +117,7 @@ mips_cpu_control control( //instance of the 'mips_cpu_control' module called 'co
 mips_cpu_regfile regfile(
 //Inputs to refile
     .clk(clk), //clock input for triggering write port
+    .rst(reset),
     .readreg1(in_readreg1), //read port 1 selector
     .readreg2(in_readreg2), //read port 2 selector
     .writereg(in_writereg), //write port selector
@@ -125,6 +127,7 @@ mips_cpu_regfile regfile(
 //Outputs from regfile
     .readdata1(out_readdata1), //read port 1 output
     .readdata2(out_readdata2), //read port 2 output
+    .vaddr(ALURes_offset), //base+offset[1:0]
     .regv0(register_v0) //debug output of $v0 or $2 (first register for returning function results
 );
 

rtl/mips_cpu_regfile.v

@@ -1,5 +1,6 @@
 module mips_cpu_regfile(
 input logic clk, //clock input for triggering write port
+input logic rst,
 input logic[4:0] readreg1, //read port 1 register selector
 input logic[4:0] readreg2, //read port 2 register selector
 input logic[4:0] writereg, //write port register selector
@@ -8,6 +9,7 @@ input logic regwrite, //enable line for write port
 input[5:0] opcode, //opcode input for controlling partial load weirdness
 output logic[31:0] readdata1, //read port 1 output
 output logic[31:0] readdata2, //read port 2 output
+input logic[1:0] vaddr, //partial read offset from ALUout
 output logic[31:0] regv0 //debug output of $v0 or $2 (third register in file/ first register for returning function results)
 );
 
@@ -25,13 +27,20 @@ assign regv0 = memory[2]; //assigning debug $v0 line to $2 of memory
 assign readdata1 = memory[readreg1]; //combinatorially output register value based on read port 1 selector
 assign readdata2 = memory[readreg2]; //combinatorially output register value based on read port 2 selector
 
+always_ff @(posedge rst) begin
+	integer i; //Initialise to zero when reset
+    for (i = 0; i < 32; i++) begin
+        memory[i] = 0;
+    end
+end
+
 always_ff @(negedge clk) begin
 	if (writereg == 5'b00000) begin
 		// skip writing if rd is $0
 	end else if (regwrite) begin
 		case (opcode)
 			6'b100000: begin //lb, load byte
-				case (readdata1[1:0])	
+				case (vaddr)	
 					2'b00: memory[writereg] <= {{24{writedata[7]}}, writedata[7:0]};
 					2'b01: memory[writereg] <= {{24{writedata[15]}}, writedata[15:8]};
 					2'b10: memory[writereg] <= {{24{writedata[23]}}, writedata[23:16]};
@@ -39,7 +48,7 @@ always_ff @(negedge clk) begin
 				endcase // readdata1[1:0]
 			end
 			6'b100100: begin //lbu, load byte unsigned
-				case (readdata1[1:0])
+				case (vaddr)
 					2'b00: memory[writereg] <= {{24{1'b0}}, writedata[7:0]};
 					2'b01: memory[writereg] <= {{24{1'b0}}, writedata[15:8]};
 					2'b10: memory[writereg] <= {{24{1'b0}}, writedata[23:16]};
@@ -47,19 +56,19 @@ always_ff @(negedge clk) begin
 				endcase // readdata1[1:0]
 			end
 			6'b100001: begin //lh, load half-word
-				case (readdata1[1:0]) // must be half-word aligned, readdata1[0] = 0
+				case (vaddr) // must be half-word aligned, readdata1[0] = 0
 					2'b00: memory[writereg] <= {{16{writedata[15]}}, writedata[15:0]};
 					2'b10: memory[writereg] <= {{16{writedata[31]}}, writedata[31:16]};
 				endcase // readdata1[1:0]
 			end
 			6'b100101: begin //lhu, load half-word unsigned
-				case (readdata1[1:0]) // must be half-word aligned, readdata1[0] = 0
+				case (vaddr) // must be half-word aligned, readdata1[0] = 0
 					2'b00: memory[writereg] <= {{16{1'b0}}, writedata[15:0]};
 					2'b10: memory[writereg] <= {{16{1'b0}}, writedata[31:16]};
 				endcase // readdata1[1:0]
 			end
 			6'b100010: begin //lwl, load word left
-				case (readdata1[1:0])
+				case (vaddr)
 					2'b00: memory[writereg][31:24] <= writedata[7:0];
 					2'b01: memory[writereg][31:16] <= writedata[15:0];
 					2'b10: memory[writereg][31:8] <= writedata[23:0];
@@ -67,7 +76,7 @@ always_ff @(negedge clk) begin
 				endcase // readdata1[1:0]
 			end
 			6'b100110: begin //lwr, load word right
-				case (readdata1[1:0])
+				case (vaddr)
 					2'b00: memory[writereg][31:0] <= writedata[31:0];
 					2'b01: memory[writereg][23:0] <= writedata[31:8];
 					2'b10: memory[writereg][15:0] <= writedata[31:16];
@@ -81,4 +90,4 @@ always_ff @(negedge clk) begin
 	end
 end
 
-endmodule
+endmodule