Deep-Sleep is a special mode in which the PS is suspended and waiting a wake-up signal. The wake can be triggered by the MIO, the USB, or the RTC.
Upon wake, the PS does not have to go through the boot process, and the security state of the system is preserved. The device consumes the lowest power during this mode while still maintaining its boot and security state.
In this mode, all the blocks outside the low-power domain, such as the system monitor and PLLs, are powered down. In LPD, Cortex-R5F is powered down. Because this mode has to preserve the context, TCM and OCM are in a retention state.