RTOS/AM5728: PCIe PHY loopback support

Manjula KS

Part Number: AM5728

Tool/software: TI-RTOS

The AM5728 TRM says PCIe PHY loopback is supported in RC mode. But I dont see any SERDES CFG register to enable Tx and Rx Loopback. Which register I need to modify to support PHY Loopback mode.

Please tell me what changes I need to make in order to test in loopback mode

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

The RTOS team have been notified. They will respond here.

0 lding over 7 years ago in reply to Biser Gatchev-XID

TI__Guru* 95265 points

Hi,

I looked the AM572x TRM, I didn't find info how to do PCIE loopback. I asked the HW team and will update here.

Regards, Eric

0 Manjula KS over 7 years ago in reply to lding

Intellectual 430 points

Hi Eric,

any update on this. I have a evmam5728 board and want to test RC loopback mode.

Regards,

Manjula

0 lding over 7 years ago in reply to Manjula KS

TI__Guru* 95265 points

Hi,

Sorry for the delay! We don't have the sample code for PCIE loopback. There are some registers can be configured for loopback, but you need to enable a bit error counter to check the link quality, that is quite difficult to do. The loopback is technical possible, but not practical. Do you have any reason to do loopback? You may directly try a RC to EP setup.

Regards, Eric

0 Manjula KS over 7 years ago in reply to lding

Intellectual 430 points

Hi,

I dont have two evms to test RC and EP setup. but, I want to test the RC PHY loopback using EDMA to excercise EDMA support to PCIE. I do want to know which registers i can modify to achieve loopback as I am not seeing any registers in the TRM. There is PIPE loopback bit in the register but that doesn't excercise the Rx and Tx path.

Please help me in testing RC Phy loopback.

Thanks & Regards

Manjula

0 lding over 7 years ago in reply to Manjula KS

TI__Guru* 95265 points

Hi,

We have tested the PCIE with EDMA using two EVMs connected, there is a PCIE driver sample in the package: processors.wiki.ti.com/.../Processor_SDK_RTOS_PCIe

How to setup PCIE loopback info is very limited in the TRM. The best way is to obtain another AM57x EVM for this testing. Or you can download Linux and test the AM57x as RC with a typical PCIE NIC or WiFi or USB card.

What is your concern of testing PCIE + EDMA, functionality or throughput? We have some benchmaeking number here: e2e.ti.com/.../2174066. It is about 357MB/s for GEN2 x 1

Regards, Eric

Processors

Processors forum

RTOS/AM5728: PCIe PHY loopback support