实验现象：

三色led轮流闪烁，具体的逻辑分析仪使用教程请参考iCore3逻辑分析仪例程

核心代码：

module signal_ctrl(    input clk_25m,    input rst_n,    output fpga_ledr,    output fpga_ledg,    output fpga_ledb);//--------------------cnt_led-------------------------------//    reg led_clk;always @(posedge clk_25m or negedge rst_n)    if (!rst_n)        begin            led_clk <= 1'd0;            cnt_led <= 25'd0;        end    else if(cnt_led == 25'd8000000)        begin            cnt_led <= 25'd0;            led_clk <= ~led_clk;        end    else cnt_led <= cnt_led + 1'd1;//--------------------led----------------------------------//            reg [2:0]led;reg [24:0]cnt_led;always @(posedge led_clk or negedge rst_n)    if (!rst_n)        begin            led <= 3'd1;        end    else        begin            if (led[2])                begin                    led <= 3'd1;                end            else                 begin                    led <= led << 1'd1;                end        endassign {fpga_ledr,fpga_ledg,fpga_ledb} = ~led;//--------------------endmodule--------------------------//    endmodule

源代码下载链接：

链接： 密码：1qfu

iCore4链接：