TE0701-05 JTAG failure?

[markh]

After updating CPLD firmware, the USB-JTAG on this board does not work. The problem is not necessarily a consequence of updating the CPLD firmware - could be hardware damage - as we are not sure whether the board was successfully used since the CPLD firmware update.

The symptom is that regardless of the position of the JTAGEN switch, both Lattice and Xilinx tools do not detect the CPLD and FPGA when doing a JTAG scan.
Both sets of tools do recognise the FTDI USB-JTAG device.

Other info:
the CPLD firmware is "good" as another board that was updated at the same time is working as expected.
LED D1 is on

I would like to try reprogramming the CPLD, but as the lattice programmer can't communicate with it, is there another way (e.g. JTAG pins next to S3)?

Mark

[Antti Lukats]

Hi

the switch on TE0701 hard-enables the CPLD JTAG chain, so it must be visible.
FTDI connects directly to CPLD JTAG, so there is nothing that can be wrong, and there is also little to no hope to gain access over other jtag adapter.
The 6 pin holes on PCB are parallel to CPLD JTAG, but to get access there FTDI should be placed into tristate first. We never used this method.

two possibilities:

1)

CPLD was accidentially programmed with jedec file that
* disables JTAG
* disables JTAG muxing
* enables SPI or I2C flashin of the CPLD

2) CPLD damaged

in such case the CPLD would not be recognized any more in JTAG chain







br
Antti Lukats

[markh]

Update: no hardware problem, double software problem (both with Vivado).

First we tried it on a Linux PC.
Then we tested on a Windows PC - when that failed, I posted on the forum as we have other TE0701s that work fine on that PC.

However, after a reboot (probably restart of the Xilinx hardware manager would have been sufficient), the PC was able to use the board normally.
Windows how I love you... not!

P.S. The Linux PC turned out to need the magic Digilent USB-JTAG drivers.

[Antti Lukats]

welcome aboard!

win is usable, but you need to KILL hw_server manually so 20 times a day.

on linux custom driver install may be needed

so it can work, but .. so far Xilinx has never managed to have reliable JTAG on any OS...