RE: AM2431: Inter-processor Communication between R5F and M4F

Hello Nathan,

Getting Started Resources

You can find some getting started information about the kinds of inter-processor communication (IPC) that are offered on AM243x here:
https://software-dl.ti.com/mcu-plus-sdk/esd/AM243X/10_00_00_20/exports/docs/api_guide_am243x/IPC_GUIDE.html
https://software-dl.ti.com/mcu-plus-sdk/esd/AM243X/10_00_00_20/exports/docs/api_guide_am243x/DRIVERS_IPC_NOTIFY_PAGE.html
https://software-dl.ti.com/mcu-plus-sdk/esd/AM243X/10_00_00_20/exports/docs/api_guide_am243x/DRIVERS_IPC_RPMESSAGE_PAGE.html

Where IPC_Notify and IPC_RPMsg are used to pass small amounts of data between cores. If you set up a shared memory region, then I would probably suggest using IPC_Notify as your notification mechanism (i.e., send a mailbox when the shared memory region is ready to be consumed by the other core).

Benchmark test results are here:
 https://software-dl.ti.com/mcu-plus-sdk/esd/AM243X/10_00_00_20/exports/docs/api_guide_am243x/DATASHEET_AM243X_EVM.html#autotoc_md122 

Other potentially helpful stuff 

I wrote the multicore academy module for AM64x from the perspective of a Linux + MCU+ SDK system. However, I still cover a lot of useful concepts about IPC here:
https://dev.ti.com/tirex/explore/node?a=7qm9DIS__LATEST&node=A__AUE83PRMo.8eEVGecstaxg__AM64-ACADEMY__WI1KRXP__LATEST 

Benchmark code? 

I am reassigning your thread to another team member to comment on whether there is a good shared memory example you can reference.

Our test code is not currently packaged in the MCU+ SDK that you can download on ti.com. However, you can still access test code on the new github repository. For example, our benchmarking code for the IPC_Notify example is here:
https://github.com/TexasInstruments/mcupsdk-core/tree/next/test/drivers/ipc_notify

Regards,

Nick

Potentially less useful stuff: 

We do have a shared memory example for Linux to MCU+ cores on the AM64x here:
https://git.ti.com/cgit/rpmsg/rpmsg_char_zerocopy/

So worst-case you could potentially look at that project to get some ideas. However, I would NOT start with that project. The AM64x R5F code in that project was written BEFORE the memory configurator tool was added in SDK 9.1, so the sysconfig settings are all wrong for later SDKs.

If you are going to try playing around with the rpmsg_char_zerocopy example, please read my response here from September 11:
https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1410313/am6442-communication-latency-issues-between-a53-and-r5-in-a-linux-rt-system/5407807#5407807

But again, I would NOT suggest spending any time on that example unless there are no other shared memory templates to work off of.

Regards,

Nick

Hi Nick,

Thanks again for all the detailed information.

The customer is still having some questions (more detailed) regarding a few of these topics.

Can I arrange a call with them that will include you and them to go over these topics?

Thanks & Regards,

Nathan 

We will continue the call discussion offline.

From the examples Tushar linked, it looks like the only shared memory example is this one:
https://software-dl.ti.com/mcu-plus-sdk/esd/AM243X/latest/exports/docs/api_guide_am243x/EXAMPLES_DRIVERS_IPC_SPINLOCK_SHAREDMEM.html 

Hopefully that can be used as a starting point for development.

Regards,

Nick