Clear backup registers by wakeup pin

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by mtb98 on Tue Sep 30 05:57:57 MST 2014
Using an LPC4357 development board and LPC4337 board see the same behavior.

Having problems getting the backup registers to clear with an event on the wakeup0 pin. Setup the event monitor with ERCONTRO set to 0xC000000A this enables GPCLEAR-EN0 and EV0-INPUT_EN and set sample clock to 1Khz.  Take the wakeup0 pin from low to high and see ERSTATUS go to 0x00000009 with GP-CLEARED and EV0 set. Also the ERCOUNTER increments for COUNTER0, and I get timestamps for the event.  But when I look at the backup registers (REGFILE) they are not cleared they contain same values as before the wakeup0 pin was cycled. 

Am I missing a register I need to configure?