13.5.1 Reset Flag Register

All flags are cleared by writing a '1' to them. They are also cleared by a Power-on Reset, with the exception of the Power-On Reset Flag (PORF).
Name: RSTFR
Offset: 0x00
Reset: 0xXX
Property: -

Bit 76543210 
 UPDIRFSWRFWDRFEXTRFBORFPORF 
Access RRR/WR/WR/WR/WR/WR/W 
Reset 00xxxxxx 

Bit 5 – UPDIRF UPDI Reset Flag

This bit is set if a UPDI Reset occurs.

Bit 4 – SWRF Software Reset Flag

This bit is set if a Software Reset occurs.

Bit 3 – WDRF Watchdog Reset Flag

This bit is set if a Watchdog Reset occurs.

Bit 2 – EXTRF External Reset Flag

This bit is set if an External Reset occurs.

Bit 1 – BORF Brown-Out Reset Flag

This bit is set if a Brown-out Reset occurs.

Bit 0 – PORF Power-On Reset Flag

This bit is set if a Power-on Reset occurs.

This flag is only cleared by writing a '1' to it.

After a POR, only the POR flag is set and all other flags are cleared. No other flags can be set before a full system boot is run after the POR.