Reprogram max3000A when JTAG was disable.

[Altera_Forum]

Hello Every body,I get trouble with my design. I programmed Max3000A(epm3256), but i disabled JTAG. Now, i want to reprogram,how can i do?could you show me how to enable JTAG or reprogram EMP3256 without JTAG?i read in this thread http://www.alteraforum.com/forum/showthread.php?t=25392&highlight=reprogram+max3000a+when+jtag+was+disable. 

But it still can not solve my problem. Thanks in advance!

[Altera_Forum]

I think the term one way ticket describes the JTAG-disable option correctly. Without a suitable high voltage programmer, you can't undo it. But personally I don't have additional informations about the details, simply because I don't need it.

[Altera_Forum]

thanks for your quick reply.I think so.I really want to reprogram my Chip.Do you know other way can program Chip without JTAG?for example using ISP.But i dont know clearly,i spend a lot of time for finding it.Thanks for your support.

[Altera_Forum]

Ask Altera, which programmers are supporting non-JTAG programming of MAX 3000. Altera programming unit (APU) e.g. did, but it isn't manufactured any more. I expect, that some industry standard programmers will also support it.

[Altera_Forum]

Thanks so much!Actually, my Chip already soldered on application board,i dont want remove it for reprogramming, that`s why im trying to find way that can reprogram via JTAG(even JTAG was disable) or other easy way.but now i know that is impossible.any way, thank you so much.hope that can recieve your supports in near future.

[Altera_Forum]

Yes, I guess in-system-programming isn't possible without special prerequisites in board design, as far as I know, at least for one special pin, the voltage must be raised to a level above VCC.