Enabling Wake-Up Feature:
- Program Control module MMR to assert "WKEN" for each IO (To enable Wakeup feature of IO)
- Write the bit PRM_IO_PMCTRL[8] WUCLK_CTRL to 1 to assert high the signal WUCLKIN.
- Write the bit PRM_IO_PMCTRL[8] WUCLK_CTRL to 0 to assert low the signal WUCLKIN.
- This will latch WKEN, Latch the current pad input value.
- The PRCM register PRM_IO_PMCTRL[9] WUCLK_STATUS logs the signal WUCLK of the last pad of the IO ring.(Should be 0).
Device goes into sleep mode (There is no need to put IO in ISOLATION and hence no need to toggle ISOCLKIN and ISOIN (As core supply is still ON)) :
- WKUP event is generated by one of the IOs
- WUOUT of the last IO is asserted HIGH.
- Because of #9, PRM interrupt is generated towards MPU/Host processor
- MPU/Host processor disables the WUKP feature of each IO and power up the required domains.
DISABLING WKUP feature:
- Write the bit PRM_IO_PMCTRL[8] WUCLK_CTRL to 1 to assert high the signal WUCLKIN.
- Write the bit PRM_IO_PMCTRL[8] WUCLK_CTRL to 0 to assert low the signal WUCLKIN.
- The PRCM register PRM_IO_PMCTRL[9] WUCLK_STATUS logs the signal WUOUT of the last pad of the IO ring.