Flashing TE0725LP-01-72C-1U XMOD-JTAG adapter TE0790 / JTAG-SMT3-NC

[naveen-krishnan]

Hello,
I am a newbie to FPGA programming, please could anyone help me out with the JTAG adapters for flashing. Right now we are using Arty A7 development board for our project and we are moving to TE0725LP-01-72C-1U for the finished product. The Trenz Wiki has mentioned to use XMOD-JTAG adapter TE0790(which has inbuilt CPLD), but in our project we would like to us JTAG-SMT3-NC(which has NO inbuilt CPLD), which is very compact and easily solderable in our application board. I tried to find answers why the signals of JTAG and UART are routed through CPLD instead of direct connection to the FPGA but could not find one. 

Please could anyone let us know if we can use JTAG-SMT3-NC for programming the TE0725LP-01-72C-1U or I need XMOD-JTAG adapter TE0790 to program?

Thanks in advance.

Regards,
Naveen

[JH]

Hi,
JTAG-SMT3-NC is also possible. you most only connect all JTAG and UART pins correctly between programmer and TE0725LP module
Schematics of the module is available on the download area: https://shop.trenz-electronic.de/en/TE0725LP-01-72C-1U-FPGA-Module-with-Xilinx-Artix-7-100T-Variante-2L-2-x-50-Pin-1.8V-supply?path=Trenz_Electronic/Modules_and_Module_Carriers/3.5x7.3/TE0725LP/REV01/Documents
br
John

[naveen-krishnan]

Hello John,
Thanks for your quick reply. That is indeed a great thing for us.
Please may I know the purpose of CPLD in XMOD-JTAG adapter TE0790 ?

Thanks in advance.

Regards,
Naveen

[JH]

Level translator and you can change pinout and functionality if needed.
br
John

[naveen-krishnan]

Thanks for helping out.

Regards,
Naveen

[naveen-krishnan]

Hello everyone,
Need your help with PROG_B connection. I am little confused with the PROG_B connection from JTAG-SMT3-NC.

In XMOD-JTAG adapter TE0790, the PROG_B is controlled by the CPLD(through NRST), I guess it does HIGH->LOW->HIGH to finish the configuration process.

As JTAG-SMT3-NC does not have a CPLD in it, should I just NRST pin of the JB1 to a push button ? I would like to know whether the pulsing of PROG_B is mandatory for the TE0725LP-01-72C-1U to boot from SPI or not, please could you help me out.

Thanks in advance.

Regards,
Naveen

[Waldi3141]

Hi,

the NRST can be connected via a resistor to a push button like on the TE0790 -> xmod schematic page 3. The PIN (G) is not controlled by the te0790 cpld, only read.
https://shop.trenz-electronic.de/de/TE0790-03-XMOD-FTDI-JTAG-Adapter-Xilinx-kompatibel?path=Trenz_Electronic/JTAG_Programmer/TE0790/REV03/Firmware

[naveen-krishnan]

Hello Waldi3141,
Thanks for your reply.

But I see PIN [G] connected to CPLD's PB9B/SI/SISPI  ? So this means there is just a physical connection but this pin is unused in CPLD ?

Thanks in advance.

Regards,
Naveen

[JH]

Hi,
no. Pin G is connected to CPLD andd S1 Pusbutton of the TE0790, see schematics page 3:
https://shop.trenz-electronic.de/de/TE0790-03-XMOD-FTDI-JTAG-Adapter-Xilinx-kompatibel?path=Trenz_Electronic/JTAG_Programmer/TE0790/REV03/Documents
CPLD has internal pullup and use this signal as input also for LED: https://wiki.trenz-electronic.de/display/PD/TE0790+CPLD+-+XMOD+Standard#TE0790CPLDXMODStandard-LED

On TE0725, Pin G is connected to TPS pin MR_N which controls PROG_B (TE0725LP schematic page 3). This pin can be left unconnected.

You can connect NRST from JTAG-SMT3-NC,. Polarity is the same, but this is not  what Digilent intends to do with it. You can try out if it works...
por_b polartity changes force only reboot, this can be also done via software over JTAG or simple power off/on the module.
br
John

[naveen-krishnan]

Hello John,
Thanks alot for clearing out the doubt.

I will update the post with the evolution of the project.

Regards,
Naveen