/*** 
 *** Configuring the Device in STANDBY sleep mode
 *** Selecting the STANDBY mode in the (SLEEPCFG.SLEEPMODE) register
 ***/
PM->SLEEPCFG.bit.SLEEPMODE = PM_SLEEPCFG_SLEEPMODE_STANDBY_Val;

/*** Ensure register is written before issuing wfi command ***/
while(PM->SLEEPCFG.bit.SLEEPMODE!=PM_SLEEPCFG_SLEEPMODE_STANDBY_Val);

/*** WAIT FOR IRQ instruction ***/
__WFI();