数字集成电路设计-3-除法器的verilog简单实现（续）

引言

1，改成clk方式。

2，添加clk,50MHz。

3, 添加rst，同步复位。

4，添加calc_done,指示计算完成，高有效。

3.1 模块代码

/*
* module:div_rill
* file name:div_rill.v
* syn:yes
* author:network
* modify:rill
* date:2012-09-10
*/

module div_rill
(
input clk,
input rst,
input[31:0] a, 
input[31:0] b,

output reg [31:0] yshang,
output reg [31:0] yyushu,
output reg calc_done
);

reg[31:0] tempa;
reg[31:0] tempb;
reg[63:0] temp_a;
reg[63:0] temp_b;

reg [5:0] counter;

always @(a or b)
begin
    tempa <= a;
    tempb <= b;
end

always @(posedge clk)
begin
	if(!rst)
		begin
			temp_a <= 64'h0000_0000_0000_0000;
			temp_b <= 64'h0000_0000_0000_0000;	
			calc_done <= 1'b0;
		end
	else
		begin
			if(counter <= 31)
				begin
					temp_a <= {temp_a[62:0],1'b0};
					if(temp_a[63:32] >= tempb)
						begin
							temp_a <= temp_a - temp_b + 1'b1;
						end
					else
						begin
							temp_a <= temp_a;
						end
						
					counter <= counter + 1;
					calc_done <= 1'b0;
				end
			else
				begin
					counter <= 0;
					calc_done <= 1'b1;
					temp_a <= {32'h00000000,tempa};
					temp_b <= {tempb,32'h00000000}; 
					yshang <= temp_a[31:0];
					yyushu <= temp_a[63:32];
				end


		end

end

endmodule

/*************** EOF ******************/

3.2 testbench

/*
* module:div_rill_tb
* file name:div_rill_tb.v
* syn:no
* author:rill
* date:2012-09-10
*/


`timescale 1ns/1ns

module div_rill_tb;

reg clk;
reg rst;
reg [31:0] a;
reg [31:0] b;
wire [31:0] yshang;
wire [31:0] yyushu;
wire calc_done;

initial
begin
	clk = 0;
	rst = 0;
	#20 rst = 1;
	
	#40 a = $random()%10000;
		b = $random()%1000;
		
	#1000 a = $random()%1000;
		b = $random()%100;
		
	#1000 a = $random()%100;
		b = $random()%10;	
		
	#1000 $stop;
end

always #10 clk = ~clk;


div_rill DIV_RILL
(
.clk (clk),
.rst (rst),
.a (a),
.b (b),

.yshang (yshang),
.yyushu (yyushu),
.calc_done (calc_done)
);

endmodule
/******** EOF ******************/

3.3 仿真

注：最新修正的版本在：http://blog.csdn.net/rill_zhen/article/details/23370323