ATTIny13-12PI ATMEL Corporation, ATTIny13-12PI Datasheet - Page 100

• Manufacturer Part Number: ATTIny13-12PI
• Description: 8-bit AVR Microcontroller with 1K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

Memory
Programming
Program And Data
Memory Lock Bits
100
ATtiny13
This section describes the different methods for Programming the ATtiny13 memories.
The ATtiny13 provides two Lock bits which can be left unprogrammed (“1”) or can be
programmed (“0”) to obtain the additional security listed in Table 43. The Lock bits can
only be erased to “1” with the Chip Erase command.
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,
should always debugWIRE be disabled by clearing the DWEN fuse.
Table 42. Lock Bit Byte
Note:
Table 43. Lock Bit Protection Modes
Notes:
LB2
LB1
LB Mode
Lock Bit Byte
1
2
3
Memory Lock Bits
1. “1” means unprogrammed, “0” means programmed
1. Program the Fuse bits before programming the LB1 and LB2.
2. “1” means unprogrammed, “0” means programmed
LB2
1
1
0
(1)
LB1
Bit No
1
0
0
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 High-voltage and Serial Programming mode.
The Fuse bits are locked in both Serial and High-voltage
Programming mode.
Further programming and verification of the Flash and
EEPROM is disabled in High-voltage and Serial
Programming mode. The Fuse bits are locked in both
Serial and High-voltage Programming mode.
is disabled.
(1)(2)
–
–
–
–
–
–
Lock bit
Lock bit
Description
(1)
debugWire is disabled.
Default Value
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
(1)
2535B–AVR–01/04
debugWire