Datasheet

2. See WDTCR - Watchdog Timer Control Register for details.
Table 31-4 Fuse High Byte
Fuse High Byte Bit No. Description Default Value
OCDEN
(4)
7 Enable OCD 1 (unprogrammed, OCD
disabled)
JTAGEN
(5)
6 Enable JTAG 0 (programmed, JTAG enabled)
SPIEN
(1)
5 Enable Serial Program and Data
Downloading
0 (programmed, SPI prog.
enabled)
CKOPT
(2)
4 Oscillator options 1 (unprogrammed)
EESAVE 3 EEPROM memory is preserved through the
Chip Erase
1 (unprogrammed, EEPROM
not preserved)
BOOTSZ1 2 Select Boot Size (see table Boot Size
Configuration in section ATmega64A Boot
Loader Parameters for details)
0 (programmed)
(3)
BOOTSZ0 1 Select Boot Size (see table Boot Size
Configuration in section ATmega64A Boot
Loader Parameters for details)
0 (programmed)
(3)
BOOTRST 0 Select Reset Vector 1 (unprogrammed)
Note:
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 Clock Sources for
details.
3. The default value of BOOTSZ1:0 results in maximum Boot Size. See table Boot Size Configuration
in section ATmega64A Boot Loader Parameters.
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 disabled. This to
avoid static current at the TDO pin in the JTAG interface.
Table 31-5 Fuse Low Byte
Fuse Low Byte Bit No. Description Default Value
BODLEVEL 7 Brown out detector trigger level 1 (unprogrammed)
BODEN 6 Brown out detector enable 1 (unprogrammed, BOD disabled)
SUT1 5 Select start-up time 1 (unprogrammed)
(1)
SUT0 4 Select start-up time 0 (programmed)
(1)
CKSEL3 3 Select Clock source 0 (programmed)
(2)
CKSEL2 2 Select Clock source 0 (programmed)
(2)
Atmel ATmega64A [DATASHEET]
Atmel-8160E-ATmega64A_Datasheet_Complete-09/2015
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