ATMEga64L ATMEL Corporation, ATMEga64L Datasheet - Page 291

• Manufacturer Part Number: ATMEga64L
• Description: 8-bit AVR Microcontroller with 64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

Fuse Bits
2490G–AVR–03/04
Table 117. Lock Bit Protection Modes
Notes:
The ATmega64 has three fuse bytes. Table 118 - Table 120 describe briefly the func-
tionality of all the fuses and how they are mapped into the fuse bytes. Note that the
fuses are read as logical zero, “0”, if they are programmed.
Table 118. Extended Fuse Byte
Notes:
Fuse Low Byte
–
–
–
–
–
–
M103C
WDTON
1
2
3
4
Memory Lock Bits
(1)
1. Program the Fuse bits before programming the Lock bits.
2. “1” means unprogrammed, “0” means programmed
1. See “ATmega103 and ATmega64 Compatibility” on page 4 for details.
2. See “Watchdog Timer Control Register – WDTCR” on page 55 for details.
(2)
1
1
0
0
Bit no
7
6
5
4
3
2
1
0
1
0
0
1
Description
–
–
–
–
–
–
ATmega103 compatibility mode
Watchdog Timer always on
Protection Type
No restrictions for SPM or LPM accessing the Boot Loader
section.
SPM is not allowed to write to the Boot Loader section.
SPM is not allowed to write to the Boot Loader section,
and LPM executing from the Application section is not
allowed to read from the Boot Loader section. If Interrupt
Vectors are placed in the Application section, interrupts
are disabled while executing from the Boot Loader section.
LPM executing from the Application section is not allowed
to read from the Boot Loader section. If Interrupt Vectors
are placed in the Application section, interrupts are
disabled while executing from the Boot Loader section.
(2)
(Continued)
ATmega64(L)
Default Value
1
1
1
1
1
1
0 (programmed)
1 (unprogrammed)
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