Dear all,i have a custom board, with stratix II, and Cyclone II, till today i dont have any problem in downloading code, and debug with JTAG port, but today i got "Error: Can't access JTAG chain Error: Operation failed" , when i try to program, programmer is working with other boards, and all fine, only this 2 board, does anybody have solution, if i have to correct the board. and work for jtag regards baba
Hi babashipDid you find a solution to this problem - I have the same problem. Boards that have worked for ages suddenly stop talking to the USB-Blaster. The boards seem to work otherwise but won't communicate via JTAG. Cheers batfink
--- Quote Start --- Same problem here, but My board is Altera Cyclone EP1C12Q240C8. Any help appreciated.. --- Quote End --- i have the same problem with you. i have two board that can't access JTAG chain when i try to program it. what will be the problem?? my ics are ep1c12q240c8 and ep2c5q208cn.
I also have the problem, my chip is EP2C8Q208, I use byteblasterII to download the program, when I use the AS mode, it can work. but when I choose the JTAG mode, it doesn't work now, several days ago it can work. I checked the circuit around the JTAG, there are no problems with the soldering. Is there anybody solve this problem? Thank you.
The power supply connection to your board might not be proper configured. The connection which comes the voltage regulator (+5v G -5V) has to be connected in a proper manner. Check them out again.
--- Quote Start --- The power supply connection to your board might not be proper configured. The connection which comes the voltage regulator (+5v G -5V) has to be connected in a proper manner. Check them out again. --- Quote End --- I checked this, I found the net TCK to ground is about 80 ohm, whereas other nets are all about 10k. The problem is similar with below: http://www.alteraforum.com/forum/showthread.php?t=6340&highlight=jtag
Has anybody solved this problem? I have a cyclone IV chip that was working fine for a week or so and today it stopped working with the JTAG chain. Boots fine from the existing program in the EPCS device.I have JTAG powered by 2.5 V which is correct for the cyclone chip. I look at TDI and the CLK pin and it is what you would expect- 2.5 V signals. I look at the TDO and it responds, but the output is only .5V. Obviously this is why it isn't working, but why is it so low? The programmer works on other boards that run on 3.3V. Did this chip blow out? what could cause this?