ATMEGA48V_09 ATMEL [ATMEL Corporation], ATMEGA48V_09 Datasheet - Page 284

• Manufacturer Part Number: ATMEGA48V_09
• Description: 8-bit Microcontroller with 8K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

27. Memory Programming
27.1
284
Program And Data Memory Lock Bits
ATmega48/88/168
The ATmega88/168 provides six Lock bits which can be left unprogrammed (“1”) or can be pro-
grammed (“0”) to obtain the additional features listed in
erased to “1” with the Chip Erase command.The ATmega48 has no separate Boot Loader sec-
tion. The SPM instruction is enabled for the whole Flash if the SELFPRGEN fuse is programmed
(“0”), otherwise it is disabled.
Table 27-1.
Notes:
Table 27-2.
Notes:
BLB12
BLB11
BLB02
BLB01
LB2
LB1
LB Mode
Lock Bit Byte
1
2
3
(2)
(2)
(2)
(2)
1. “1” means unprogrammed, “0” means programmed
2. Only on ATmega88/168.
1. Program the Fuse bits and Boot Lock bits before programming the LB1 and LB2.
2. “1” means unprogrammed, “0” means programmed
Memory Lock Bits
Lock Bit Byte
Lock Bit Protection Modes
LB2
1
1
0
(1)
LB1
1
0
0
Bit No
7
6
5
4
3
2
1
0
Protection Type
No memory lock features enabled.
Further programming of the Flash and EEPROM is disabled in
Parallel and Serial Programming mode. The Fuse bits are
locked in both Serial and Parallel Programming mode.
Further programming and verification of the Flash and EEPROM
is disabled in Parallel and Serial Programming mode. The Boot
Lock bits and Fuse bits are locked in both Serial and Parallel
Programming mode.
(1)(2)
Description
–
–
Boot Lock bit
Boot Lock bit
Boot Lock bit
Boot Lock bit
Lock bit
Lock bit
(1)
Table
27-2. The Lock bits can only be
Default Value
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
2545R–AVR–07/09
(1)