Datasheet

225
ATtiny828 [DATASHEET]
8371A–AVR–08/12
22. Lock Bits, Fuse Bits and Device Signature
22.1 Lock Bits
ATtiny828 provides the program and data memory lock bits listed in Table 85.
Table 85. Lock Bit Byte
Notes: 1. “1” means unprogrammed, “0” means programmed.
Lock bits can be left unprogrammed (“1”) or can be programmed (“0”) to obtain the additional features listed in Table 86,
Table 87, and Table 88.
Table 86. Lock Bit Protection Modes
Notes: 1. “1” means unprogrammed, “0” means programmed.
2. Program fuse bits before programming LB1 and LB2.
The general read/write lock bits do not control reading/writing by LPM/SPM. SPM and LPM access to application and
boot loader sections is controlled by boot lock bits, listed in Table 87 and Table 88.
Lock Bit Byte Bit No Description See Default Value
(1)
– 7 – 1 (unprogrammed)
– 6 – 1 (unprogrammed)
BLB12 5
Boot lock bit Page 226
1 (unprogrammed)
BLB11 4 1 (unprogrammed)
BLB02 3 1 (unprogrammed)
BLB01 2 1 (unprogrammed)
LB2 1
Lock bit Below
1 (unprogrammed)
LB1 0 1 (unprogrammed)
Lock Bits
(1)
Mode of ProtectionLB2 LB1
1 1 No memory lock features enabled
1 0
Further programming of Flash and EEPROM is disabled in parallel and serial programming
mode. Fuse bits are locked in both serial and parallel programming mode
(2)
0 1 Reserved
0 0
Further reading and programming of Flash and EEPROM is disabled in parallel and serial
programming mode. Fuse bits are locked in both serial and parallel programming mode
(2)