JTAG timing constraints

Hello Anand,

Thanks for trying to help.

1. JTAGEN on both boards is pulled up (10K to 3.3V)

2. All three pins pulled up to 2.5V using 10K Res. (They are on bank 8, where the VCCIO is 2.5V I referred sec 1.1.2 of the Max 10 'Pin connection guidelines' document)

3. TDI and TMS also pulled up by 10K but to 2.5V, as per the same sec 1.1.2 of the 'Pin connection guidelines' document. (I did not use diodes / caps on the JTAG lines (on either of the documents) to prevent 'voltage overshoot' problem, since as per the documents it is recommended, when JTAG supply is over 2.5V)

4. CONF_DONE also stays low, along with nStatus. Only nConfig goes high, which is expected.

5. I followed 'Pin connection guidelines', the 'Max 10 Design Guidelines' and the 'Board Design Guidelines AN114' documents, for both the boards.

6a) I just tried loading the 'sof' file and it got loaded on the very first attempt! Here's the message I get..

"info (209060): started programmer operation at wed dec 06 09:34:30 2017

info (209016): configuring device index 1

info (209017): device 1 contains jtag id code 0x031820dd

info (209007): configuration succeeded -- 1 device(s) configured

info (209011): successfully performed operation(s)

info (209061): ended programmer operation at wed dec 06 09:34:31 2017"

6b) However I really need to load the POF file and this is the message I am still getting...

lo and behold.. I got it configured the first time using the POF file!!

I am using the 'exact same' setup I used yesterday evening before leaving work. Did not even move a wire, except for plugging the power connector back on! I only started with the SOF file today (which I never tried on this newer board), before the POF file.

So there's something really erratic / intermittent, which is bad as these boards are for commercial use!!

This is very similar to the comments posted at the start of this post, that JTAG configuration reliability is becoming erratic :-| !

The person (daniel@3t.nl) stated.. “jtag instability became a hot issue (e.g. random failures when discovering the jtag chain, using signaltap, using systemconsole).”

For the past two days, when using the POF file, I would only read the Device ID and then get error message something like "Error 16328: Put the device in User mode …"

Unfortunately I had to clear my browser cache and don't recall the exact message. If it re-appears I would post it.

Thanks,