ATMEGA48V_11 ATMEL [ATMEL Corporation], ATMEGA48V_11 Datasheet - Page 285

• Manufacturer Part Number: ATMEGA48V_11
• Description: 8-bit Atmel Microcontroller with 4/8/16K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

28. Memory programming
28.1
2545T–AVR–05/11
Program and data memory lock bits
The Atmel ATmega88/168 provides six Lock bits which can be left unprogrammed (“1”) or can
be programmed (“0”) to obtain the additional features listed in
be erased to “1” with the Chip Erase command.The Atmel ATmega48 has no separate Boot
Loader section. The SPM instruction is enabled for the whole Flash if the SELFPRGEN fuse is
programmed (“0”), otherwise it is disabled.
Table 28-1.
Notes:
Table 28-2.
Notes:
Lock bit byte
BLB12
BLB11
BLB02
BLB01
LB2
LB1
LB mode
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
ATmega48/88/168
Default value
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
28-2. The Lock bits can only
(1)
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