ARMLEG/src/ForwardingUnit.v at master · ronitrex/ARMLEG · GitHub

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module ForwardingUnit
(
	input [4:0] IDEX_RegisterRm,
	input [4:0] IDEX_RegisterRn,
	input [4:0] EXMEM_RegisterRd,
	input [4:0] MEMWB_RegisterRd,
	input EXMEM_RegWrite,
	input MEMWB_RegWrite,
	output reg [1:0] ForwardA,
	output reg [1:0] ForwardB
);

	always @(*) begin
		ForwardA = 2'b00;
		ForwardB = 2'b00;

		//EX hazard:
		if ((EXMEM_RegWrite) && (EXMEM_RegisterRd != 31) && (EXMEM_RegisterRd == IDEX_RegisterRn)) begin
			ForwardA = 2'b10;
		end
		if ((EXMEM_RegWrite) && (EXMEM_RegisterRd != 31) && (EXMEM_RegisterRd == IDEX_RegisterRm)) begin
			ForwardB = 2'b10;
		end

		//MEM hazard:
		if ((MEMWB_RegWrite) && (MEMWB_RegisterRd != 31) && (MEMWB_RegisterRd == IDEX_RegisterRn))
		//&& !((EXMEM_RegWrite) && (EXMEM_RegisterRd != 31) && (EXMEM_RegisterRd != IDEX_RegisterRn)))
			begin
				ForwardA = 2'b01;
			end
		if ((MEMWB_RegWrite) && (MEMWB_RegisterRd != 31) && (MEMWB_RegisterRd == IDEX_RegisterRm))
		//&& !((EXMEM_RegWrite) && (EXMEM_RegisterRd != 31) && (EXMEM_RegisterRd != IDEX_RegisterRm)))
			begin
				ForwardB = 2'b01;
			end
	end
endmodule