Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

Help:Jtag configuration of Cyclone2

When the Cyc chip was welded on my PCB. All the bins are normal .

I load an easy design via jtag to control LED to on and off. But It doesn't work. The programmer shows me 100% and successful. The voltage of the LED pin is 2.78V and the LED is on, funny indeed , the I/O port next to the LED-drived I/O port become 2.78V too. When power down, the two ports are not connected , but why the Voltage became same when power on?

I am puzzled.

Do you face this problem either?

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    18 years ago

    I assume you are assigning the pins to the right locations.

    I also assume that the design is looking to pull the I/O low to sink the LED Cathode current.

    These are the two I can think of based on the limited info provided.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    18 years ago

    Surely I assigned the pins to the right locations and the design is looking to pull the I/O low to sink the LED Cathode current.

    The funny thing is that when I tried again last night after I left my pcb alone for a whole day yesterday , It works.

    I don't know what is wrong with it and what's the problem with the PCB or FPGA.

    I am really pullzed, Avatar.