ARTY - Is encryption supported on Arty boards?

[Greg D]

Hi there,

Is encryption (via eFUSE) supported on Arty boards?

Thanks.

Greg

[JColvin]

Hi Greg,

Looking at various Xilinx documents, it seems that encryption through eFUSE would be possible on an Arty board (at least from my inexperienced eyes), but I'll ask some of our applications engineers about this; they'll get back to you here on the forum.

Thanks,
JColvin

[AndrewHolzer]

Hi Greg,

I did some digging through various Xilinx documents to find you an answer and I found that eFUSE encryption is supported on the Arty boards in Vivado 2014.4 onwards, from this page. ISE can configure a limited subset of 7 series devices via iMPACT, however the Arty isn't one of these devices. 

As far as configuring the eFUSE registers, it is beyond what we do here at Digilent. You're treading in open waters from here. I suggest that you look through the Vivado User Guides to understand how to use the tools for eFUSE configuration.

Hope this helps you,
Andrew

 

 

[Greg D]

Hi Andrew,

Thanks for the reply.

In fact, encryption is not a matter of SW tools (ISE/Vivado) only. Vivado can be used to configure eFUSE registers of Artix-7 XC7A35T. This can be done with the XILINX USB Platorm Cable II (provided that VCCAUX can provide enough current while the FPGA is not configured).

On the Arty board, a FTDI chip is used for the USB-JTAG interface. In the past, the DIGILENT JTAG-HSx cable clearly stated that eFUSE configuration was not supported (for a reason that I don't know). I suppose that this is the same on-board solution used on the Arty board. In that case, I would say that eFUSE encryption is NOT supported on Arty.

However, I had a look at the schematics and I could see that connector J8 is connected to the JTAG interface of the FPGA. The connector is not there by default but I suppose that a XILINX USB Platorm Cable II could be connected if it was.

So, my 2 questions :

1. Can't the on-board USB-JTAG solution based on the FTDI chip support eFUSE configuration (like the DIGILENT JTAG-HSx cable)?

2. Has the J8 connector been fully tested with a XILINX USB Platorm Cable II to configure eFUSE?

I need a clear answer from you since I cannot solder the connector and run the risk of burning the eFUSE registers on my board?

Thanks.

Greg

 

[AndrewHolzer]

Hi Greg,

Thank you for pointing out that encryption isn't just a matter of SW tools. I have some answers for your question, which I am happy to get into further if I don't give you a clear enough answer here.

For your first question, currently the on-board USB-JTAG solution doesn't support eFUSE configuration due to how the toolchain confirms the cable speed. This should change in Xilinx's 2016 release of Vivado. 

For your second question, the J8 connection hasn't been tested with a Xilinx USB Platform Cable II, but has been tested with plenty of other cables. You should be able to use the Platform cable to configure the eFUSE registers through the header.

Please let me know if I can further clarify anything for you,
Andrew

[Greg D]

Hi guys,

Just to confirm that we can successfully program eFUSE registers of the XC7A35T on the Arty board: We need to connect the USB Platform Cable II on a connector (J8) mounted on the bottom of the board.

Cheers,

Greg