diff --git a/rtl/mips_cpu_bus.v b/rtl/mips_cpu_bus.v index 08f9de9..2794ca6 100644 --- a/rtl/mips_cpu_bus.v +++ b/rtl/mips_cpu_bus.v @@ -29,6 +29,7 @@ logic[3:0] write_byteenable; // byteenable calculator for partial write logic clk_state; // make sure posedge and negedge of clk do not occur repeatedly logic partial_write; // flag to control datapath when doing a partial write logic[31:0] partial_writedata; // modified data for partial writes (StoreHalfword or StoreByte) +logic[31:0] write_data_address; // modified data address for partial writes initial begin clk_internal = 1'b0; @@ -93,18 +94,22 @@ always_comb begin 2'b00: begin partial_writedata = {24{1'b0}, harvard_writedata[7:0]}; write_byteenable = 4'b0001; + write_data_address = {harvard_data_address[31:2], 2'b00}; end 2'b01: begin partial_writedata = {16{1'b0}, harvard_writedata[7:0], 8{1'b0}}; write_byteenable = 4'b0010; + write_data_address = {harvard_data_address[31:2], 2'b00}; end 2'b10: begin partial_writedata = {8{1'b0}, harvard_writedata[7:0], 16{1'b0}}; write_byteenable = 4'b0100; + write_data_address = {harvard_data_address[31:2], 2'b00}; end 2'b11: begin partial_writedata = {harvard_writedata[7:0], 24{1'b0}}; write_byteenable = 4'b1000; + write_data_address = {harvard_data_address[31:2], 2'b00}; end endcase end @@ -114,18 +119,22 @@ always_comb begin 2'b00: begin partial_writedata = {16{1'b0}, harvard_writedata[15:0]}; write_byteenable = 4'b0011; + write_data_address = {harvard_data_address[31:2], 2'b00}; end 2'b01: begin // halfword address must be matrually aligned, last bit must be 0 partial_writedata = 32'hxxxxxxxx; write_byteenable = 4'bxxxx; + write_data_address = 32'hxxxxxxxx; end 2'b10: begin partial_writedata = {harvard_writedata[15:0], 16{1'b0}}; write_byteenable = 4'b1100; + write_data_address = {harvard_data_address[31:2], 2'b00}; end 2'b11: begin // halfword address must be matrually aligned, last bit must be 0 partial_writedata = 32'hxxxxxxxx; write_byteenable = 4'bxxxx; + write_data_address = 32'hxxxxxxxx; end endcase end @@ -133,6 +142,7 @@ always_comb begin partial_write = 1'b0; partial_writedata = 32'h00000000; write_byteenable = 4'b1111; + write_data_address = harvard_data_address; end endcase end @@ -184,7 +194,7 @@ always_comb begin n_state = 2'b00; end 2'b11: begin // connecting wires when in write state - address = harvard_data_address; + address = write_data_address; read = 1'b0; write = 1'b1; byteenable = write_byteenable;