Try to reverse engineer a defective board with an EP2C8

[Altera_Forum]

Hello! 

 I'm very knew to this stuff and hopefully you could explain me some things about Altera Cyclone II, because i had a defective board with such an chip and try to repair it. Therefore i need to know how it works and what options für debugging there are. So please forgive me, if i mangle some things up...  All i know by reading datasheets and the schematic of the board is, that there is an EP2C8 FPGA which is used to drive an small LCD-Screen (5" or so). There is also a EPCS4 configuration device placed, where the FPGA gets configured. Then, there is a SRAM chip and also a Flash chip (S29GL064N, 8MByte). Now i think the FPGA reads it's config from the serialdevice at POR and emulates some CPU (my best bet is NIOS), which then boots a firmware from the flash.  I managed to find the JTAG-header and connected it via an USB-Blaster. Quartus II Programmer could detect the FPGA and i added an EPCS4 device manually in the setup. Then i "Start" an it reads back an *.jic file. Inside, i guess, i find the configurationdata for the FPGA. What can i do with it?  My goal is to download the content of the Flash, because there must be some error. I had a working unit and swapped components to narrow down the cause of the error until i found the error goes with the flash. Unfortunately the Flash is in an TSOP56 case and my little Flash-reader (TL866) cannot handle it, so i want to use JTAG to readout and reprogram the content.  Can somebody help me to get further? Any help would be appreciated :-)

[Altera_Forum]

So, your goal is to download the contents of the S29GL064 - is that right? You refer to the FLASH - remember your EPCS4 is also a FLASH device but it sounds like that's working correctly. 

 Before considering reading the contents of the S29 FLASH device - what are you going to do with the binary file that you end up with? You suggest it has an error in it, which sounds like a sensible conclusion based on the description of your problem. How do you track down that problem? Decompile the binary?  As to how to read the FLASH device's contents I suggest you put together a new project, probably with a Nios, specifically aimed at reading out the contents of the FLASH. Depending on what other interfaces you have on the board you can stream it out to a file on your computer. Worst case you can put a JTAG UART in your Nios design and stream it out through that - it'll be very slow. Perhaps you have a faster I/O interface available.  Cheers, Alex