- Program And Data Memory Lock Bits
ATtiny13A provides two lock bits which can be left unprogrammed (“۱”) or can be programmed
(“۰”) to obtain the additional security listed in Table 17-2 on page 103. The lock bits can be
erased to “۱” with the Chip Erase command, only.
Program memory can be read out via the debugWIRE interface when the DWEN fuse is programmed, even if the lock bits are set. Thus, when lock bit security is required, debugWIRE
should always be disabled by clearing the DWEN fuse.
Note: 1. “۱” means unprogrammed, “۰” means programmed
Table 17-1. Lock Bit Byte
| Lock Bit Byte | Bit No | Description | Default Value (1) |
| 7 | – | ۱ (unprogrammed) | |
| 6 | – | ۱ (unprogrammed) | |
| 5 | – | ۱ (unprogrammed) | |
| 4 | – | ۱ (unprogrammed) | |
| 3 | – | ۱ (unprogrammed) | |
| 2 | – | ۱ (unprogrammed) | |
| LB2 | 1 | Lock bit | 1 (unprogrammed) |
| LB1 | 0 | Lock bit | 1 (unprogrammed) |
Table 17-2. Lock Bit Protection Modes