JTAG pin sharing in MAX10

liron87 · ‎04-08-2021

I would like to know if I can use the option of JTAG pin sharing "on the fly" by toggle JTAG_EN pin (switch back and forth between user I/O pins and dedicated JTAG pin)?

NurAiman_M_Intel · ‎04-09-2021

Hi,

Thank you for contacting Intel community.

Per Intel Max 10 pin connection guideline,

Intel suggest when to use JTAG pins as regular I/O pins, tie the JTAGEN pin to a weak 1-kΩ pull-down. To use JTAG pin as dedicated pin, tie the JTAGEN pin to a weak 10-kΩ pull-up.

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/dp/max-10/pcg-01018.pdf (page 6).

Regards,

Aiman

liron87 · ‎04-13-2021

Thanks but can I toggle JTAG_EN from user I/O to JTAG "on the fly" ?

NurAiman_M_Intel · ‎04-13-2021

Hi,

JTAGEN is a dual-purpose pin. This pin functions according to the setting of the JTAG pin sharing option bit. If the JTAG pin sharing is not enabled, the JTAGEN pin is a regular I/O pin and JTAG pins function as JTAG dedicated pins.

If the JTAG pin sharing is enabled and the JTAGEN pin is pulled low, JTAG pins function as dual-purpose pins. If the JTAG pin sharing is enabled and the JTAGEN pin is pulled high, JTAG pins function as JTAG dedicated pins

Hence, if the pin is dedicated pin, it can't be used using user I/O mode.

Regards,

Aiman

liron87 · ‎04-25-2021

Hi,

I'm using 10M08 Evaluation Kit with the following configurations:

- JTAG pin sharing is enabled

- JTAGEN pin is pulled high

- FPGA sample JTAG pins as inputs regardless to JTAGEN state and I can't access JTAG (can't access the device) .

It doesn't fit with the configuration user guide

The only solution for access the device is to erase CFM while nconfig low

Please advise

Thanks,

Liron

NurAiman_M_Intel · ‎04-20-2021

Hi,

We do not receive any response from you to the previous question/reply/answer that I have provided. This thread will be transitioned to community support. If you have a new question, feel free to open a new thread to get the support from Intel experts. Otherwise, the community users will continue to help you on this thread. Thank you.

Regards,

Aiman