module mips_cpu_bus_memory( //Avalon memory mapped bus controller (slave) input logic clk, input logic[31:0] address, input logic write, input logic read, output logic waitrequest, input logic[31:0] writedata, input logic[3:0] byteenable, output logic[31:0] readdata ); parameter INSTR_INIT_FILE = ""; parameter DATA_INIT_FILE = ""; logic [31:0] data_memory [0:63]; // location 0x00001000 onwards logic [31:0] instr_memory [0:63]; // location 0xBFC00000 onwards initial begin for (integer i=0; i<$size(data_memory); i++) begin //Initialise data to zero by default data_memory[i] = 0; end for (integer i=0; i<$size(instr_memory); i++) begin //Initialise instr to zero by default instr_memory[i] = 0; end if (INSTR_INIT_FILE != "") begin //Load instr contents from file if specified $display("RAM: Loading RAM contents from %s", INSTR_INIT_FILE); $readmemh(INSTR_INIT_FILE, instr_memory); end for (integer i = 0; i<$size(instr_memory); i++) begin //Read out instr contents to log $display("byte +%h: %h", 32'hBFC00000+i*4, instr_memory[i]); end if (DATA_INIT_FILE != "") begin //Load data contents from file if specified $display("MEM: Loading MEM contents from %s", DATA_INIT_FILE); $readmemh(DATA_INIT_FILE, data_memory); end else begin $display("MEM FILE NOT GIVEN"); end for (integer i = 0; i<$size(data_memory); i++) begin //Read out data contents to log $display("byte +%h: %h", 32'h00001000+i*4, data_memory[i]); end end always_ff @(posedge read or posedge write) begin waitrequest <= 1; end always_ff @(posedge clk) begin if (waitrequest) begin if (read) begin // read code end else if (write) begin // write code end else begin waitrequest = 1'bx; readdata = 32'hxxxxxxxx; end end else begin waitrequest = 1'b0; readdata = 32'h00000000; end end endmodule