Tool/software:
Backup mode is expected to work as follows:
Host software sets (arms) EN_BACKUP=1 while input source is attached at VBUS
Input voltage fails below backup mode trigger point = %*VINDPM
Backup mode engages setting Disable both ACDRV =1 then EN_OTG=1 to regulate PMID = VOTG
VBUS Status reports backup mode
VINDPM status reports VINDPM/VOTG
VAC1 status reports not present since input source was removed
Host software periodically Monitors for VAC1 status = present
Input source reattached
AC1 present status changes to VAC1 present
Host software sets Force ACFET1 on =1 which causes charger to auto set DISACDRV=0
VBUS Status changes to Normal OTG Mode
Host writes EN_OTG=0 in order to switch back to input source
Charger reenters charge mode, assuming EN_CHG=1 and /CEpin=0 and auto sets EN_BACKUP=1 (rearms)