EP2C5Q208C7 Cyclone II device configuration problem with EPCS1 in AS mode

[Altera_Forum]

Dear all, 

 I am trying to configure Cyclone II EP2C5Q208C7 device with EPCS1 in Active serial mode using a USB blaster.   I am not using JTAG configuration on my board so connected the TDI/TMS PIN to VCC(3.3V) and TCK to GND. but i have not put any external pull up or pull down register in these.  for EPCS1 AS configuration interface I have made connections as per the CycloneII hand book and have used 10 k register as pull up and pull down for nSTATUS, nCONFIG, CONFIG_DONE and nCE Pins.  I am using Quartus II 9.0 web edition software.  I am generating the .pof file after manually converting the .sof file from files menu using convert programming file and compression is on.  my problems are as follows:  At the first moment my FPGA got programmed properly using this mode and worked fine.  The next time I tried to programme EPCS1 in ISP mode it gave error as can't recognize silicon ID for device 1 with the same setups including Power supply, USB blaster, PC, Quartus II software.   And FPGA was not getting programmed, it was generating clk at DCLK Pin and Pulses at nCS Pins.   I tried to program it on another PC with all other setup same. => same error.  Then I tried to program it with another USB blaster(though it's from the same lot we got indented at once=>not sure if there can be any difference) at another PC with all other setups same=> it programmed EPCS1 correctly without any error. I was happy.  But the FPGA is not getting programmed now. nSTATUS, nCONFIG, CONFIG_DONE Pins are not getting released and stuck at logic low.  I tried to reprogramme the EPCS1 on my earlier original setup where "Silicon ID not recognized" error was popping and same old USB blaster => to my surprise it programmed the EPCS1 without any error but FPGA is not getting configured. => i see nSTATUS, nCONFIG, CONFIG_DONE Pins are low continuously. means device not coming out of POR (Power On Reset) mode.  How can I resolve this problem? (I have tried to re programme EPCS1 and it's getting reprogrammed now correctly)  At the same time I would be interested to know why such problems happening? it seems quite random.  could there be any problem due to i did not use pull up/down registers at TDI/TMS and TCK Pins? should there be registers compulsarily? (expert advice needed)  If there could be any problem in PCB connections, device would not have been programmed even once. but it worked fine for first attempt.   Please help!!  Thanks in advance.

[Altera_Forum]

could somebody help me in this regard?

[Altera_Forum]

Could somebody help me on this? 

 Now i have got another board wired and have put the recommended 1k ohm pull up/down resistors on TDI/TMS and TCK Pins while connecting them to VCC and GND.  my device got programmed fine for many a times and worked fine. But today i tried to reprogram it again and got the following error  "can't recognise the silicon ID for device 1"  why this could happen? It was working absolutely fine and suddenly this reprogram did not work.  If somebody could suggest any solution plz do suggest. I need it desperately!!!  thanks in advance!!!  mohan

[Altera_Forum]

Hi,  

I observed similar problems while doing prototyping. Many times "broken" cards could be reused by changing the FPGA (I had a TQFP package), sometimes the EPCS1 needed to be replaced as well. Between perfect operation and "nothing anymore" it worked sometimes, sometimes not... I never really identified the reason but problems stopped by ensuring the GND of the USB-Blaster being the first signal connected to the target PCB with the FPGA. Thus I assume the programming pins might be damaged by overvoltage by static discharge if these and not the GND line is connected first. (The USB-Master was referenced to PC, the FPGA to it's powersupply, somewhat all being capacitive referenced to earth...) This either ends in connecting and disconnecting the USB Blaster only with the target being completely unpowered (disconnected from power line) or (as I did) connect the GND of the Byteblaster permanently with the target (I use an adapter from the USB-Blaster connector to the smaller connector on the target anyway) Taking a look in the datasheet for Cyclone III and IV, they have added protection circuit to the programming pins to keep voltages at DCLK, DATA, ... within devices limits...   Maybe this does not solve your problem but helps to scratch other cards...  Carlhermann