11-05-2013 10:54 AM
Hi All,I have a Cyclone IV GX Dev Kit but I believe many of the kits are built the same way so the issue / solution may be applicable to others. The devkit has MAX II device which acts as a configuration controller. It selects between a factory image and a user image on power up and when the reset buttons are pressed. By using the image select / reset buttons on the board, I can load both the factory image (left as default) and my user image successfully and everything works as it should. On power up though there is a dip switch which selects which image is loaded. In factory position this works fine. However, when the dip switch selects user image, the user image is loaded and works correctly for approx 2 seconds. After the two seconds are up the board resets and the factory image is loaded. I'm guessing that the MAX II config controller has some sort of watchdog built into it and it requires something to be sent to it to stop it resetting the board. Unfortunately, I can't find anything in the rather limited documentation. Does anybody know what I am missing? Cheers, Colin
01-03-2014 12:45 PM
Thanks - I finally received the same info from Altera this morning. It is a pity that this has been a known issue with V12.1 of the code but there is no errata on the dev kit webpage warning people about it.For info, the reset after 2 seconds is caused by the PFL reset code at the bottom of max_c4gx.vhd of the MAX II code.