题解 | #Johnson Counter#
Johnson Counter
http://www.nowcoder.com/practice/7ee6e9ed687c40c3981d7586a65bc22d
开始这么写：
`timescale 1ns/1ns
module JC_counter(
input clk ,
input rst_n,
output reg [3:0] Q
);
always@(posedge clk or negedge rst_n)begin
if(!rst_n) Q <= 'd0;
else if(!Q[0]) Q <= {1'b1, Q[3 : 1]};
else Q <= {1'b0, Q[3 : 1]};
end
endmodule
看了答案这么写
`timescale 1ns/1ns
module JC_counter(
input clk ,
input rst_n,
output reg [3:0] Q
);
always@(posedge clk or negedge rst_n)begin
if(!rst_n) Q <= 'd0;
else Q <= {~Q[0], Q[3 : 1]};
end
endmodule
