题解 | #ROM的简单实现#

`timescale 1ns/1ns
module rom(
	input clk,
	input rst_n,
	input [7:0]addr,
	
	output wire [3:0]data
);

reg [3:0] reg_rom[7:0];
reg [3:0] data_reg    ; 
integer i = 0;
always@(posedge clk or negedge rst_n)begin
	if(!rst_n)begin
         for( i = 0; i <=7 ; i = i + 1)
		 begin
			 reg_rom[i] <= i*2;
		 end 
	end
	else begin
		for( i = 0; i <=7 ; i = i + 1)
		 begin
			 reg_rom[i] <= reg_rom[i];
		 end 
	end
	    
end

always@(*)begin
	if(!rst_n)
	    data_reg = 4'd0;
    else begin
		data_reg = reg_rom[addr];
	end
end

assign data = data_reg;
endmodule