Forum Discussion

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

First time writing to EPCQ

Hi,

I am facing a strange problem.

I was able to write to EPCQ256 using SPI port (without using Quartus Programmer). All things that has to do with byte swapping and communication with EPCQ were fine and running properly.

When I received a new fresh development boards, the SPI writing to EPCQ did not work!

When I write to EPCQ using Quartus programmer, it works fine.

When I try again writing to EPCQ through SPI, everything goes fine.

I tried the option "Disable EPCQ ID chekc" but it did not help.

Has anybody idea where could be the problem?

2 Replies

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

    For fresh EPCQ device you need to write the NVCR value. If you have use Quartus II programmer to write the PECQ first time this will set the NVCR value.

    Then when you write the EPCQ next time without Quartus II programmer, the NVCR value still retain. Thus I believe that the reason why the configuration to FPGA was successful.

    If you did not use Quartus II programmer to access fresh EPCQ device, then you need to set the NVCR by yourself. You can refer to the KDB solution link for the detail or from the EPCQ device datasheet:

    https://www.altera.com/support/support-resources/knowledge-base/solutions/rd07072013_869.html