PCIE on CMOD-A735T

[Charles Li]

Hello, I am trying to use the 7 Series FPGAs Integrated Block for PCI Express v3.3 ip on my CMOD A7-35T, which has a xc7a35tcpg236-1 on it, but the ip does not show up on the ip catalog. I speculated it was because the ip does not support this part, but the device seems to meet the Minimum Device Requirements listed in the ip documentation (albeit only x2 and Gen 1). Googled around a bit and didn't find anything. The documentation even specifies the xc7a35tcpg236. When I try out other devices, the ip shows up

https://www.xilinx.com/support/documentation/ip_documentation/pcie_7x/v3_3/pg054-7series-pcie.pdf

Thanks ahead of time!

[zygot]

In general the T designator for Xilinx devices indicates that it has transceivers which are required for PCIe. This doesn't imply that all boards using a transceiver equipped part can implement PCIe or even use the transceivers. The CMOD products are not suitable for doing transceiver based designs. I have the Diligent Genesys board that has a Virtex 5 FPGA device with transceivers and they are unusable for a variety of reasons. You should read the reference manuals for Xilinx PCIe as well as the application notes and other information that they provide to learn about FPGA based PCIe.

[jpeyron]

Hi @Charles Li,

Welcome to the Digilent Forums!

To meet a specific tier of development board not all of the FPGA's capabilities are facilitated in every Digilent FPGA development board. Here is the Cmod A7 resource center. On the schematic for the Cmod A7 you can see on page 3 what pins have been routed on banks 14, 16, 34 and 35.

Here is a list of Digilent boards that have the transceivers routed.

Zedboard

Nexys Video

Genesys 2

NetFPGA Sume

best regards,

Jon