AMD recommends implementing an intentional shutdown sequence to allow software running on the platform to cleanly shutdown file systems and interface transactions. Both software and hardware requested shutdown features noted for the platform management unit (PMU) are available. Both require you to account for these and enable them in their production MPSoC-PMU firmware configuration.
When no consideration is given to the PS, nor operating system, asserting PWROFF_C2M_L can be used to immediately begin a power down at the power supply level. The following sequence assumes that the SOM 5.0 V power supply is sustained during the power down sequence. With that assumption, the power sequencer devices should remove the power rails in the correct order without waiting for the operating system to cleanly shutdown.