AM623: Is is feasible to reset without ethernet switch?

Ethernet in PRU refer to this:

Hi, Experts

It looks like it is OK, please help to double check this and give us advice how to implement this.

Regards

Zekun

Hello Zekun,

Please keep in mind that AM62x PRU subsystem is PRUSS, NOT PRU-ICSS (like you would find on parts like AM335x/AM437x/AM57x), or PRU_ICSSG (like on AM24x/AM64x/AM65x). AM62x PRU subsystem does NOT support industrial communication, or PRU Ethernet in general.
You can find more information here: https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/09_02_01_09/exports/docs/common/PRU-ICSS/Overview.html 

If you need PRU Ethernet on your device, we can discuss what other parts might be a good fit for your design.

If you are using CPSW Ethernet on your device, that would be controlled by Linux A53 cores, not the PRU cores.

Regards,

Nick

Hi, Nick

Thanks for your detailed explanation. Now I am clear about usage of PRU.

If we want to use CPSW controlled by A53, could we make it that warm reset with isolation of CPSW?

Regards

Zekun

Hello Zekun,

My assumption is that you would NOT be able to isolate the CPSW from getting reset, but I am not the CPSW expert so that might be incorrect.

Before I pass your thread to another team member, what exactly are you hoping for by isolating the CPSW?

The CPSW is not able to do networking on its own - the software stack for networking is on the A53 cores, not the CPSW. So even if the CPSW did not get reset, it would be unable to send networking packets (I am not sure if it would be able to receive a limited number of networking packets or not). My assumption (that we can check with another team member if needed) is that Linux would still want to re-negotiate the network link once the Linux drivers booted back up. So from the perspective of the rest of your network, I am not sure whether there would be any difference between CPSW getting reset with the rest of the system, and CPSW not getting reset with the rest of the system.

Regards,

Nick

Hi Nick

Thanks, from my understanding there is no difference between rest or without rest of cpsw. Let me check further with customer about this. We can hold the thread for now. 

Thanks

Zekun

Hello Zekun,

Sounds good. I'll send your thread over to our CPSW owner now, so they can comment if I got anything wrong.

Regards,

Nick

Hello Zekun,

I have split your question about AM24x / AM64x into a new thread, and assigned the new thread to our PRU Ethernet team:
https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1352050/am24x-am64x-can-pru-ethernet-stay-up-while-main-domain-resets 

FYI, AM243x & AM64x are basically identical, except that AM243x does not have A53 cores, so you cannot run Linux on the AM243x.

Regards,

Nick