m_key_led.v

一个用verilog语言实现的包含：键盘扫描

module  m_key_led(
            clk,
            rstb,
            //led
            led,
            //key
            xrow,
            ycol,
            //
            keyvalue
            );
input       clk, rstb;
output  [3:0]   led;

output  [3:0]   xrow;
input   [3:0]   ycol;
output  [15:0]  keyvalue;


wire    [15:0]  keyvalue;
reg	[3:0] led;
always  @(keyvalue)
case(keyvalue)
16'h1:      led = 14;
16'h2:      led = 13;
16'h4:      led = 12;
16'h8:      led = 11;
16'h10:     led = 10;
16'h20:     led = 9;
16'h40:     led = 8;
16'h80:     led = 7;
16'h100:    led = 6;
16'h200:    led = 5;
16'h400:    led = 4;
16'h800:    led = 3;
16'h1000:   led = 2;
16'h2000:   led = 1;
16'h4000:   led = 0;
16'h8000:   led = 0;
default:    led = 15;
endcase

m_keyscan
    u_keyscan(
            .clk        (clk),
            .rstb       (rstb),
            //
            .clkdiv     (20'h10000),
            //
            .keyvalue   (keyvalue),
            //
            .x          (xrow),
            .y          (ycol)
            );

endmodule