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Altera_Forum's avatar
Altera_Forum
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7 years ago

Cyclone IV EP4CE10F17C8N Chip: Light LED

Hello All,

This is my first time using an FPGA, my independent research is currently using the book "RTL Hardware Design Using VHDL" by Pong Chu.

I have purchased an Altera Cyclone IV with a EP4CE10F17C8N chip. I am programming using Quartis Prime Lite, in VHDL. I am programing the board with a USB Blaster, all drivers installed.

My aim was to test a simple code by turning on an on-board LED. I do not see anything wrong with the VHDL Code and I have no compilation error, yet I do not see any LED turned on (aside from the power LED). This leads me to belive it may be the pin assignment.

I am using the following data sheet:

https://www.waveshare.com/w/upload/c/c8/coreep4ce10-schematic.pdf

(https://www.waveshare.com/w/upload/c/c8/coreep4ce10-schematic.pdf)

And assigned LED to PIN_D12

My Code is as follows:


library ieee;	use ieee.std_logic_1164.all;
	use ieee.numeric_std.all;
	
ENTITY light IS
	PORT(--X1 : IN STD_LOGIC;
	LED : OUT STD_LOGIC := '0'
		
	);
END light;
ARCHITECTURE LogicFunction OF light IS
BEGIN
	LED <= '1';
END LogicFunction;

I am not sure why I can not light the LED, any help will be much appreciated. Thank you in advance!

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor

    Hi,

    From schematic LED will turn on when you assign LED <= '0' and will turn of when LED <= '1'.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor

    --- Quote Start ---

    Yes, the LED is active low.

    --- Quote End ---

    Got it, thank you all! So I was able to light the LED knowing it is active LOW. I.e. I changed LED <= '1'; to a 0.

    Thanks again!