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Altera_Forum
Honored Contributor I
1,397 Views

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!
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3 Replies
Altera_Forum
Honored Contributor I
66 Views

Hi,  

 

From schematic LED will turn on when you assign LED <= '0' and will turn of when LED <= '1'.
Altera_Forum
Honored Contributor I
66 Views

Yes, the LED is active low.

Altera_Forum
Honored Contributor I
66 Views

 

--- 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!