11.5.1 Control A

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

Bit 76543210 
  CMD[6:0] 
Access R/WR/WR/WR/WR/WR/WR/W 
Reset 0000000 

Bits 6:0 – CMD[6:0] Command

Write this bit field to enable or issue a command. The Chip Erase and EEPROM Erase commands are started when the command is written. The others enable an erase or write operation. The operation is started by doing a store instruction to an address location.

A change from one command to another must always go through No command (NOCMD) or No operation (NOOP) command to avoid the Command Collision error being set in the ERROR bit field from the NVMCTRL.STATUS register.

ValueNameDescription
0x00NOCMDNo command
0x01NOOPNo operation
0x02FLWRFlash Write Enable
0x08FLPERFlash Page Erase Enable
0x09FLMPER2Flash 2-page Erase Enable
0x0AFLMPER4Flash 4-page Erase Enable
0x0BFLMPER8Flash 8-page Erase Enable
0x0CFLMPER16Flash 16-page Erase Enable
0x0DFLMPER32Flash 32-page Erase Enable
0x12EEWREEPROM Write Enable
0x13EEERWREEPROM Erase and Write Enable
0x18EEBEREEPROM Byte Erase Enable
0x19EEMBER2EEPROM 2-byte Erase Enable
0x1AEEMBER4EEPROM 4-byte Erase Enable
0x1BEEMBER8EEPROM 8-byte Erase Enable
0x1CEEMBER16EEPROM 16-byte Erase Enable
0x1DEEMBER32EEPROM 32-byte Erase Enable
0x20CHERErase Flash and EEPROM. EEPROM is skipped if EESAVE fuse is set. (UPDI access only.)
0x30EECHERErase EEPROM
Other-Reserved