Datasheet

32. Memory Programming (MEMPROG)
32.1 Program And Data Memory Lock Bits
The device provides six Lock bits. These can be left unprogrammed ('1') or can be programmed ('0') to
obtain the additional features listed in the table Lock Bit Protection Modes below. The Lock bits can only
be erased to '1' with the Chip Erase command.
Table 32-1. Lock Bit Byte
(1)
Lock Bit Byte Bit No. Description Default Value
7 – 1 (unprogrammed)
6 – 1 (unprogrammed)
BLB12 5 Boot Lock bit 1 (unprogrammed)
BLB11 4 Boot Lock bit 1 (unprogrammed)
BLB02 3 Boot Lock bit 1 (unprogrammed)
BLB01 2 Boot Lock bit 1 (unprogrammed)
LB2 1 Lock bit 1 (unprogrammed)
LB1 0 Lock bit 1 (unprogrammed)
Note:
1. '1' means unprogrammed, '0' means programmed.
Table 32-2. Lock Bit Protection Modes
(1)(2)
Memory Lock Bits Protection Type
LB Mode LB2 LB1
1 1 1 No memory lock features enabled.
2 1 0 Further programming of the Flash and EEPROM is disabled in Parallel and Serial
Programming modes. The Fuse bits are locked in both Serial and Parallel
Programming modes.
(1)
3 0 0 Further programming and verification of the Flash and EEPROM is disabled in
Parallel and Serial Programming modes. The Boot Lock bits and Fuse bits are
locked in both Serial and Parallel Programming modes.
(1)
Note:
1. Program the Fuse bits and Boot Lock bits before programming the LB1 and LB2.
2. '1' means unprogrammed, '0' means programmed.
ATmega48PA/88PA/168PA
Memory Programming (MEMPROG)
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40002011A-page 364