ATmega32(L)
Table 103. Lock Bit Protection Modes (Continued)
Memory Lock Bits(2)
Protection Type
No restrictions for SPM or LPM accessing the Boot Loader
section.
1
2
1
1
1
0
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.
3
0
0
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.
4
0
1
Notes: 1. Program the fuse bits before programming the Lock bits.
2. “1” means unprogrammed, “0” means programmed
Fuse Bits
The ATmega32 has two fuse bytes. Table 104 and Table 105 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 104. Fuse High Byte
FuseHigh
Byte
Bit
No.
Description
Enable OCD
Enable JTAG
Default Value
OCDEN(4)
JTAGEN(5)
7
6
1 (unprogrammed, OCD disabled)
0 (programmed, JTAG enabled)
Enable SPI Serial Program and
Data Downloading
SPIEN(1)
CKOPT(2)
EESAVE
5
4
3
0 (programmed, SPI prog. enabled)
1 (unprogrammed)
Oscillator options
EEPROM memory is preserved
through the Chip Erase
1 (unprogrammed, EEPROM not
preserved)
Select Boot Size (see Table 99
for details)
BOOTSZ1
2
0 (programmed)(3)
Select Boot Size (see Table 99
for details)
BOOTSZ0
BOOTRST
1
0
0 (programmed)(3)
1 (unprogrammed)
Select reset vector
Notes: 1. The SPIEN Fuse is not accessible in SPI Serial Programming mode.
2. The CKOPT Fuse functionality depends on the setting of the CKSEL bits. See See
“Clock Sources” on page 25. for details.
3. The default value of BOOTSZ1..0 results in maximum Boot Size. See Table 99 on
page 255.
4. Never ship a product with the OCDEN Fuse programmed regardless of the setting of
Lock bits and the JTAGEN Fuse. A programmed OCDEN Fuse enables some parts of
the clock system to be running in all sleep modes. This may increase the power
consumption.
5. If the JTAG interface is left unconnected, the JTAGEN fuse should if possible be dis-
abled. This to avoid static current at the TDO pin in the JTAG interface.
257
2503J–AVR–10/06
ATMEL [ ATMEL ]
