speed grade of two artix-a7 (picture in appendix)

[john-con]

Hello together,

sorry for the stupid question, but I have hard problems finding the speed grade of two artix-a7. I bought the Arty-A7 and the Basys 3 board. Unfortunately, I cannot find their speed grade (-1, -2, -3L or whatever). The xilinx sources say, it should be written on the chip, but stupid me cannot find it. Can anybody help me further, please?

Thank you and best regards, john

[JColvin]

Hi @john-con,

I can confirm that the Arty A7 and Basys 3 both use speed grade 1 components.

I'm not certain off hand where you would readily determine this off of the chip labeling itself, but you can see the critical "-1" portion of the FPGA name in the right hand side of their respective Resource Centers, https://digilent.com/reference/programmable-logic/arty-a7/start and https://digilent.com/reference/programmable-logic/basys-3/start, of the "FPGA Part #" row.

As far as I know, zygot is correct that only Digilent's Genesys 2 has a speed grade 2 part.

Let me know if you have any questions.

Thanks,
JColvin

[zygot]

Gee, as someone who generally thinks that there are no stupid questions, yours should be close to being in that category... but it isn't.

The answer ( but probably not ) is in UG475 where AMD Series7 packages are described. In the device marking section there's a long description of what you might encounter ( or not encounter ) while looking at the IC markings. There's no guarantee that there's any text telling you what speed grade a particular part is. There's probably a 2D bar code and like many AMD documents, instead of including the answer where you'd expect to see it, you get a reference to yet another document to find and read. This is typical of FPGA documentation.

I can save you the trouble though as the cost of -2 or -3 speed grade parts makes it extremely unlikely that Digilent would use the more expensive device just to complete a production run without charging a premium for the finished product. The Genesys2 is the only Digilent board that I know of with a speed grade part faster than -1.. Edited February 16 by zygot

[zygot]

There have been -1L Arty boards with lower performance than -1 parts, so knowing the speed grade might be important. You should go by what Digilent claims.

Still it would be nice if all device markings indicated the speed and temperature grade in an obvious manner. I've run into ICs where the only indication of what the part is consists of a code that you need to find a document to decipher. Edited February 17 by zygot

[john-con]

Thank you very much @JColvin and @zygot for your help and clarification.

[JColvin]

Minor follow up, I looked at the UG475 that zygot referenced, and best that I can tell from Chapter 6 Package Marking, the speed grade used to be its own individual line on the 4th row down, just below the lot code (detailed slightly more in Table 6-1). But based on figure 6-4 for the Artix FPGA (and the equivalent figures for the Kintex and Virtex FPGAs), this is the "Legacy Artix-7 Device Package Marking".

I'm not certain when this change occurred, but it was a number of years ago as I have Basys 3 Rev C's (Rev D came out in 2021) both with the speed grade marking and without it.

Thanks,
JColvin