103
8126F–AVR–05/12
ATtiny13A
17. Memory Programming
This section describes how ATtiny13A memories can be programmed.
17.1 Program And Data Memory Lock Bits
ATtiny13A provides two lock bits which can be left unprogrammed (“1”) or can be programmed
(“0”) to obtain the additional security listed in Table 17-2 on page 103. The lock bits can be
erased to “1” with the Chip Erase command, only.
Program memory can be read out via the debugWIRE interface when the DWEN fuse is pro-
grammed, 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. “1” means unprogrammed, “0” means programmed
Notes: 1. Program fuse bits before lock bits. See section “Fuse Bytes” on page 104.
2. “1” means unprogrammed, “0” means programmed
Table 17-1. Lock Bit Byte
Lock Bit Byte Bit No Description Default Value
(1)
7 – 1 (unprogrammed)
6 – 1 (unprogrammed)
5 – 1 (unprogrammed)
4 – 1 (unprogrammed)
3 – 1 (unprogrammed)
2 – 1 (unprogrammed)
LB2 1 Lock bit 1 (unprogrammed)
LB1 0 Lock bit 1 (unprogrammed)
Table 17-2. Lock Bit Protection Modes
Memory Lock Bits
(1)
(2)
Protection TypeLB Mode LB2 LB1
1 1 1 No memory lock features enabled.
210
Further programming of the Flash and EEPROM is disabled in
High-voltage and Serial Programming mode. Fuse bits are
locked in both Serial and High-voltage Programming mode.
debugWire is disabled.
300
Further programming and verification of the Flash and
EEPROM is disabled in High-voltage and Serial Programming
mode. Fuse bits are locked in both Serial and High-voltage
Programming mode. debugWire is disabled.
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