9.5.1 Control A

Name: CTRLA
Offset: 0x00
Reset: 0x00
Property: Configuration Change Protection

Bit 76543210 
      CMD[2:0] 
Access R/WR/WR/W 
Reset 000 

Bits 2:0 – CMD[2:0] Command

Write this bit field to issue a command. The Configuration Change Protection key for self-programming (SPM) has to be written within four instructions before this write.
ValueNameDescription
0x0 - No command
0x1 WP Write page buffer to memory (NVMCTRL.ADDR selects which memory)
0x2 ER Erase page (NVMCTRL.ADDR selects which memory)
0x3 ERWP Erase and write page (NVMCTRL.ADDR selects which memory)
0x4 PBC Page buffer clear
0x5 CHER Chip erase: Erase Flash and EEPROM (unless EESAVE in FUSE.SYSCFG is ‘1’)
0x6 EEER EEPROM Erase
0x7 WFU Write fuse (only accessible through UPDI)