Forum Discussion

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

Cyclone III LS doesn't boot w/o ByteBlaster

I am using a Cyclone III LS, using JTAG to program during development, and a Serial Configuration Device to load the FPGA once that is finished.

I programmed the .jic file into the SCD in order for a colleague (who does not have Quartus) to test the board without having to program after every powerup.

The board had no function unless the ByteBlaster was connected to the JTAG connector. The ByteBlaster did not need to be connected to USB for this to work.

I've attached my JTAG connector pinout. This should be correct, since programming with the .sof poses no problems. I have also attached the schematic showing the resistors on the JTAG lines, connected per the Cyclone III Device Family Pin Connection Guidelines.

TMS is pulled up to 2.5V with a 10K resistor.

TDI is pulled up to 2.5V with a 10K resistor.

TCK is pulled down to GND with a 1K resistor.

TDO has no resisitors on it.

If anyone has any clues to a permanent solution, I would be grateful!

3 Replies

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

    Just to add a bit more information; if I program using the .sof, and then remove the ByteBlaster, it appears the FPGA is immediately disabled.

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

    Hi,

    I had a problem quite similar to your one and I found that it was a problem of console that was probably full of debug messages... You could try removing debug messages (at least only someone) or disabling default stdout to jtag (within syslib settings for old IDE or wihing BSP editor).

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

    It turned out the capacitance I had on the output of my 2.5V regulator was too little. So, the regulator wasn't outputting a full 2.5V, and therefore the Cyclone III was resetting itself. So, I bumped it up to a 10uF, and now everything seems good.