Forum Discussion

Ophir_eng's avatar
Ophir_eng
Icon for New Contributor rankNew Contributor
7 months ago

Weak pull-ups \ tri-state at cyclone v soc

Hello, we are doing a bring up for a new card, we are seeing a phenomenon and trying to understand it, the fpga is loaded by the hps, and the nconfig pin is held constant at a logical 1, when the card...
Fpga Devkit
FvM's avatar
FvM
Icon for Super Contributor rankSuper Contributor
7 months ago
  • Hi,
    connecting 10k pull-down to nconfig isn't correct. The pin should have a pull-up resistor and temporarily pulled down to trigger reconfiguration.
  • Ophir_eng's avatar
    Ophir_eng
    Icon for New Contributor rankNew Contributor
    7 months ago
    Hi, thanks you for the comment

    We have constant pull-up on nconfig so nconfig always at high position

    Some of our outpus with pull down (to make sure that the en of the power supply will be at low position until the fpga will power up and enable the power supplies according our sequence), we saw at the oscilloscope that the en assert to high to 2-3 sec and then goes low