Author Topic: Unable to list JTAG targets after CPLD update  (Read 72 times)

nitneuq

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Unable to list JTAG targets after CPLD update
« on: February 22, 2021, 07:46:37 PM »
Hello,

Me and the engineering team of my company have created a custom board based on the TE0706 and using TE0820 rev3. To program the board, a TE0790 is used.

In order to select JTAG mode I have tried to update the CPLD firmware with the JTAG/QSPI variant.
I have followed this procedure and used files for the TE0820 rev3 board.

The Lattice programmer tool told me the update was successfull but I had two problems:
  • the CPLD status led was blinking 4 times, indicating that the CPLD remained in QSPI/SD variant
  • and more important: I was not able to lists jtag thanks to xsdb Xilinx tool

So I have updated again the CPLD with the default variant (which is QSPI/SD variant according to this document, but this other document states that the default variant is QSPI).

But even by downloading again the default variant I am unable to list any target and I get the following error message when I list targets with xsdb tool:

Code: [Select]
xsdb% targets
  1 whole scan chain (DR shift through all zeroes)
xsdb%jtag targets
  1  JTAG-ONB4 251633005463A (error DR shift through all zeroes)


While before this operation I was able to list some targets.

Please, can you tell me how to solve this problem and return to the default CPLD state.

Any help would really be appreciated!

Best regards,

JH

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Re: Unable to list JTAG targets after CPLD update
« Reply #1 on: February 22, 2021, 09:55:49 PM »
Hi,
can you tell me all dip switch positions of the TE0706 and TE0790?

br
John

nitneuq

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Re: Unable to list JTAG targets after CPLD update
« Reply #2 on: February 23, 2021, 03:31:44 PM »
I have used following DIP switch positions for the TE0790 (from S2-1 to S2-4) : OFF, OFF, OFF, ON while programming the CPLD and ON, OFF, OFF, ON for normal operations to access to Zynq JTAG targets.

The TE706 switches were always (while programmming CPLD or trying to access to Zynq JTAG) set to PROGMODE = ON (low state) and MODE = OFF (not connected state).
Note that I don't understand how the Lattice programmer tool had successfully the CPLD while the PROGMODE was set to ON (according to this table, CPLD can be programmed only when PROGMODE = OFF).

bastionbooger

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Re: Unable to list JTAG targets after CPLD update
« Reply #3 on: February 23, 2021, 08:03:51 PM »
you have updated the firmware of the TE0790's CPLD.