Artix 7 Asynchronous BPI FLASH configuration for PCIe

[mustafahyuce]

Hi There,

I have been working on a design with Artix 7 (XC7A200). I would like to use the Artix-7 for the PCIe interfacing, the issue is Artix-7 does not support Tandem configuration, so the option is to use fast configuration with BPI. XAPP1179 suggests that Flat(non-tandem) with bitstream compression enable should achieve fast programming time. It looks like there is a serious end of life issue with Synchronous NOR Flashes on the market. So the most available option is to go with Asynchronous NOR flash.

Is it possible to use the Asynchronous NOR Flash configuration with EMCCLK enabled on the FPGA. I saw on the XAPP1220, they are specifying that Asynchronous mode to be run with CCLk but what is the limitation that stops them testing it with Asynch mode with EMCCLK.

Is it possible to use Asynch configuration mode with EMCCLK and what would be performance difference between the Async and Sync mode configuration.

Cheers

Mustafa

[hj · Accepted solution]

Refer to this https://www.xilinx.com/support/answers/51748.html
EMCCLK can be used in Async read mode as well.

For performance between these modes please refer to https://www.xilinx.com/support/documentation/application_notes/xapp587-bpi-fast-configuration.pdf Page 10-11 (configuration time)

Thanks

[mustafahyuce]

Hi Harshit,

Thank you very much for your response.

Looking at the answer record and the application note, asynchronous mode of configuration seems to be really bad solution for PCIe based designs.

I have come across a NOR flash from Cypress (http://www.cypress.com/file/219951/download) which is capable of doing synchronous configuration, Do you think using this part from Cypress can cause an issue? I saw in the configuration settings of Vivado there is an option for BPI Sync Mode Type1 = G18 or Type2 = P30.

Is this related to the flash device selection or any other selected NOR Flash device should work fine?

Cheers

Mustafa

[hj]

Hi Mustafa,

You can refer to UG#908 page#328 for supported flash list.
https://www.xilinx.com/support/documentation/sw_manuals/xilinx2018_2/ug908-vivado-programming-debugging.pdf

I can see this flash is not supported.

You can check this post discussion as well. https://forums.xilinx.com/t5/Configuration/How-to-Calculate-a-Time-of-7-Series-FPGA-Master-Configuration/m-p/875193#M9319

Thanks
Harshit