When a processing unit requires a peripheral or memory slave node, it must request the slave node using the power management API. After the slave node has performed its function and is no longer required, it can be released and powered off.
The following figure shows the call flow for a use case where the APU and the
RPU are sharing an on-chip memory bank, ocm0.
Figure 1. Platform Management Framework Call Sequence for APU and RPU
Sharing an On-Chip Memory Bank
Note: The
ocm0
memory remains powered on after the APU calls XStatus
XPm_ReleaseNode, because the RPU has also requested the same slave node.
After the RPU also releases the ocm0 node, then the PMC
requests the PSM to power off the ocm0 memory.