基于黑金开发板的键盘边沿检测程序

/**************************************
        The Key Edge Test
Author:luxiaolai
Date  :2011-11-29
***************************************/

module test(LED,RESET,CLOCK,KEY_UP);
input RESET,CLOCK,KEY_UP;
output [3:0] LED;
wire led_cn;
test1 U1
(
 .clk(CLOCK),
 .rst(RESET),
 .key(KEY_UP),
 .keyout(led_cn),
);
test3 U2
(
 .clk(CLOCK),
 .rst(RESET),
 .led_cn(led_cn),
 .led(LED),
);
endmodule

/**************************************
  The Key Test Part
**************************************/
module test1(clk,rst,key,keyout);
input clk,rst,key;
parameter cnt1=32'd2_00000;
reg[31:0] cnt;
reg key1,key2;
wire keyin;
always @ (posedge clk or negedge rst)
if(!rst)
 begin
  key1<=1'b1;
  key2<=1'b1;
 end
  else
  begin
   key1<=key;
   key2<=key1;
  end
assign keyin=key2&(~key1);
reg key3,key4;
output keyout;
always @ (posedge clk or negedge rst)
if(!rst)
 begin
  cnt<=0;
  key3<=1;
 end
  else if(keyin)
  begin
   cnt<=0;
   key3<=1;
   end
  else if(cnt==cnt1)
   begin
    cnt<=0;
    key3<=key;
   end
    else
     cnt<=cnt+1;
always @ (posedge clk or negedge rst)
if(!rst)
 key4<=1;
  else
   key4<=key3;
assign keyout=key4&(~key3);
endmodule

/************************************
  The Display Part
*************************************/     
module test3(led,clk,rst,led_cn);
input clk,rst,led_cn;
output reg[3:0] led;
always @ (posedge clk or negedge rst)
if(!rst)
 led<=4'b0001;
  else if(led_cn)
   begin
    led<=led+1;
    if(led==4'b1111)
    led<=0;
    end
     //else
      //led<=led;
endmodule