I posted last year about a strange problem I was having with a Flex
10K100 board. At one time, I figured out how to setup programming files so that the EPC2 would correctly configure the FPGA. Apparently, I should have written that down more than once, because I have lost the secret sauce.
I recently made a modification to the design, and tested it by directly JTAG loading the FPGA. Everything works great, I have a design that makes timing, and it works correctly when downloaded to the FPGA directly (using the .sof) file.The trouble comes when I try to load the design into the configuration PROM.
The board has a single EPF10K100GC503-3 FPGA (yes, an old-school part), and an EPC2. The configuration logic is modeled on the Altera app note exactly. I can also program the EPC2, and verify the contents, correctly. (I can verify, and extract, successfully)
However; when I cycle power, the LED's just come on and randomly flicker out, with no relationship to the clock (I suspect capacitive effects, since I'm driving the LED's through a buffer-driver chip) I am using the INIT_DONE output in the design, but it's pretty apparent that the design isn't getting loaded properly.
Now, I know the EPC2 isn't bad, nor is the board design. I have a .pof file that I extracted from the device that correctly configures the board. (starts up reliably every time) Given all this, I know it's a configuration problem - but for the life of me, I can't remember what I did the last time to get this thing going.
What have I forgotten to set in Quartus? Note, I'm using Quartus II
6.0 SP1 (webpack).
Thanks!
-Seth