DE0-nano - Implementation of a simple flashing led

Question

Hi i have tried to flash a led with 1Hz frequency but could not be able to do it. Can you pls see my code below and advise?

The project compiles fine. I have connected the 50MHz clk to a pll 1/10000 which equals 5KHz. That frequency goes into the module "pwm".

The led output is connected to the first led of the DE0-nano (bit 0).

module pwm(clock, led);

input clock; // wire

output led; reg led;

reg [31:0] ctr=0;

parameter max = 31'd5000;

// when ctr equals max save the value 0 to next_ctr, else increment ctr by one

assign next_ctr = (ctr == max) ? 31'd0 : ctr + 31'd1;

// when ctr equals max save the opposite of led_status to led_status, else save the same value

assign led_status = (ctr == max) ? led_status^1 : led_status;

// execute the assign expressions on every rising edge of the clock

always @ (posedge clock) begin

led <= led_status; // change the led status or let it as is

ctr <= next_ctr; // increment by one or reset to zero when ctr reaches 50m

end

endmodule

I googled it and found more or less similar information. Can you help?

Regards

Manos

altera_forum · Answer

Hi everyone,

I solved the issue.

module test(clock, led);

input clock; // wire

output led; reg led;

reg [31:0] ctr=0;

parameter max = 5000;

// Execute the assign expressions on every rising edge of the clock

always @ (posedge clock) begin

ctr <= (ctr == max) ? 0 : ctr + 1;

led <= (ctr == max) ? led^1 : led;

end

endmodule

Regards

Manos

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