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Altera_Forum
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15 years ago

EP2 won't AS configure, nCONFIG stuck lo

EP2C5Q208 will not AS configure itself. Circuit is exactly as Fig. 13-7, page 13-20 in Cyclone2 Device Handbook, Vol. 1 for a single device. Configuration device is EPCS4. (Using USB Blaster Quart...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Thanks Pete,

I don't exactly know what you mean by "ID the device". If you mean to use the "auto detect", then pressing this button in the Programmer does not seem to do anything. The single line entry in the programmer still shows the .sof "File" name, to the right of that EP2C5Q208 "Device", to the right of that the "Checksum" value, to the right of that FFFFFFFF "Usercode", etc.

The PLL VCCA and VCCD power terminals are filtered exactly as recommended: 10uF before and after a ferrite bead to these power terminals located real close to the FPGA. Plenty of bypassing. Solid 1.18Vdc measured, just like VCCINT terminals.

I find no short on nCONFIG pin. There's 10.8k ohms to ground and 9.7k ohms to VCCIO with the power off. When power's on, there's 0.006Vdc on nCONFIG and 0.000Vdc to a nearby ground. What I mean by this is that the nCONFIG pin is not a dead short to ground.

Help me with the "ID the device" and what do you recommend next?

Thanks a lot!