TE0710 red SysLed flashing on custom carrier board.

[sjoshi]

We are working with a custom carrier board which should host a TE0710 module. On powering up the board and module, we have noticed that the red SysLED keeps flashing continuously.

It appears that there is a design flaw where we have overlooked the SC_nRST, EN1, BOOTMODE and NOSEQ inputs to the module. The EN1 and SC_nRST pins can still be used, however BOOTMODE and NOSEQ are left unconnected in the design. On pulling SC_nRST high, the red SysLed stops flashing.

Vivado cannot detect the target even if EN1 is high or low. I am afraid that BOOTMODE or NOSEQ play a crucial role in initializing the Artix 7. We are currently using a TE0790 as the programmer. The JTAG pins have been connected in a scheme similar to that used on the TE0706.

Is there a way we can still rescue the board? Can we use a custom firmware for the onboard Lattice which can overlook the NOSEQ and BOOTMODE pin states and let us access the FPGA over JTAG? The JTAGSEL signal is pulled low.

[sjoshi]

I can program the module from a TE0705 board. When I plug the module in our carrier board and pull SC_nRST and EN1 high, the module configures itself from memory and my blinker code works. We seem to be missing JTAG access from our carrier board although I have read on the forum that the JTAG signals are simply patched through. JTAGSEL = 0 also seems to be the suggested setting.

[JH]

Hi,
JTAGSEL bin you can switch between Lattice CPLD and AMD FPGA. JTAG SEL=0 is FPGA(JTAG will forwarded through the CPLD to the FPGA). In case you use JTAGSEL=1, you should see unknown device normaly on vivado HW Manager.

Which programmer did you use on your carrier board?

Check also TDI/TDO, maybe they are swapped in your design?



BOOTMODE or NOSEQ are optional for TE0710 with native FPGA on both available firmwares and are no matter for JTAG:
https://wiki.trenz-electronic.de/display/PD/TE0710+CPLD
or older version for modules which was delivered before feb 2024:
https://shop.trenz-electronic.de/en/Download/?path=Trenz_Electronic/Modules_and_Module_Carriers/4x5/TE0710/REV03/Firmware/archive

br
John