I am trying to use the RTC alarm to wake up my 4337, from the LPCXpresso4337 board, from deep sleep or power down mode mode and I start from the LPCopen's example of pmc_states.c (using 2.20 version from lpcopen for 4337)
To make sure RTC alarm is triggered I am putting ON one LED in the interrupt. The VBAT pin stays at 3.0V all the time and I put debug to check if RTC is enabling or not, everything works fine. If I put my 43537 in deep sleep mode or power down and choose to wake up from RTC alarm event interrupt I never get RTC alarm interrupt.
If I chose the WAKE button as wake up signal it works but not with RTC!