0x02 ( 2 )  Reset
  
BitsDescription
71 if the reset signal to the expansion bus and esp is asserted
6:5Reserved
41 if multiface nmi was generated by an i/o trap (experimental, see nextreg 0xDA)
31 if multiface nmi was generated by this nextreg
21 if divmmc nmi was generated by this nextreg
11 if the last reset was a hard reset*
01 if the last reset was a soft reset*

* Only one of bits 1:0 will be set

BitsDescription
7Assert and hold reset to the expansion bus and the esp wifi (hard reset = 0)
6:5Reserved must be zero
4Clear i/o trap (write zero to clear) (experimental)**
3Generate multiface nmi (write zero to clear)**
2Generate divmmc nmi (write zero to clear)**
1Generate a hard reset (reboot)*
0Generate a soft reset*

* Hard reset has precedence

** These signals are ignored if the multiface, divmmc, dma or external nmi master is active

** Copper cannot clear these bits

** An i/o trap could occur at the same time as mf / divmmc cause; always check this bit in nmi isr if important