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AT90PWM216/316 [DATASHEET]
7710H–AVR–07/2013
24. Memory Programming
24.1
Program And Data Memory Lock Bits
The AT90PWM216/316 provides six Lock bits which can be left unprogrammed (“1”) or can be programmed (“0”) to
obtain the additional features listed in
Table 24-2. The Lock bits can only be erased to “1” with the Chip Erase
command.
Notes:
1. “1” means unprogrammed, “0” means programmed.
Notes:
1. Program the Fuse bits and Boot Lock bits before programming the LB1 and LB2.
2. “1” means unprogrammed, “0” means programmed
Table 24-1.
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)
Table 24-2.
Memory Lock Bits
Protection Type
LB Mode
LB2
LB1
1
No memory lock features enabled.
21
0
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
30
0
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)Table 24-3.
BLB0 Mode
BLB02
BLB01
1
No restrictions for SPM or LPM accessing the Application section.
2
1
0
SPM is not allowed to write to the Application section.
30
0
SPM is not allowed to write to the Application section, and LPM executing from the
Boot Loader section is not allowed to read from the Application section. If Interrupt
Vectors are placed in the Boot Loader section, interrupts are disabled while
executing from the Application section.
40
1
LPM executing from the Boot Loader section is not allowed to read from the
Application section. If Interrupt Vectors are placed in the Boot Loader section,
interrupts are disabled while executing from the Application section.