5.1 ULP1 Mode Entry Procedure

If one or more read or write accesses to the PMC user interface follow the last instruction to enter ULP1 mode (set CKGR_MOR.ULP1), the ULP1 mode may be exited immediately after the entry.

Work Around

Add two dummy read accesses outside of the PMC user interface just after setting the CKGR_MOR.ULP1 bit.

Affected Silicon Revisions