RT117x: which master can access CM4 TCM?

[mastupristi]

Hi,

First of all, it is necessary to list which masters are on the bus. Certainly CM7, CM4 and DMA are masters. What other masters are there?
USB has an internal DMA, right? So USB could be considered a master?
Does the same argument apply to ENET?

The TCM of CM4 is a slave on the bus right? Or not, since it communicates with the CM4 core via a dedicated bus?

In any case, the question is, which master can access CM4's TCM?

best regards

Max

[mastupristi]

Hi

I found Figure 2.2 in the Ref Man:

It's not so simple to understand. I understand that the CM4's TCM can be accessed by eDMA, but not USB and ENET_1G, right?

This would also be confirmed by some tests I did on USB and this github post

However, I have a working example where ENET_1G seems to be able to access the CM4's TCM. You can find it here: https://community.nxp.com/pwmxy87654/attachments/pwmxy87654/imxrt/32611/4/evkbmimxrt1170_lwip_iperf_...

Note that the RAM used in the example is exclusively TCM.

I think there needs to be a thorough explanation.

best regards

Max