bit0: power off
bit1: full reboot (unused). Discards things like [[CONFIG9_Registers#CFG9_BOOTENV|CFG9_BOOTENV]]
bit2: reboot. Preserves [[CONFIG9_Registers#CFG9_BOOTENV|CFG9_BOOTENV]], etc. bit3: reset
FCRAM (present in by LgyBg. Unused because a system reboot does the same thing & a PDN reg also implements this function.
bit4: signal that sleep mode is about to be entered (used by PTM)
Bit 4 sets a bit at a RAM address which seems to control the watcdog timer state, then this bit is immediately unmasked. This field has a bitmask of 0x0F .
| 2 bits
turns off P00 and sets it to output mode (seems to kill the entire SoC )
bit1: turns on a prohibited bit in an RTC Control register and turns P12 into an output