| module key(clk,key_in,key_out); input clk;
 input[3:0]key_in;//按键输入
 output[3:0]key_out;
 reg[3:0]dout1,dout2,dout3;
 reg[3:0]a;
 reg i;
 //assign key_out=a;
 always@(posedge clk)//按键消抖
 begin
 dout1<=key_in;
 dout2<=dout1;
 dout3<=dout2;
 a<=(dout1|dout2|dout3);
 end
 always@(posedge clk)
 begin
 if(a[0]==0) i=i+1;//按键按下,计一次数
 end
 
 
 endmodule
 怎么改,在每按一次键时,i只加1?
 |