Datasheet

Extended Fuse Byte Bit No. Description Default Value
– 5 – 0
– 4 – 0
- 3 - 0
BODLEVEL2
(1)
2 Brown-out Detector trigger level 1 (unprogrammed)
BODLEVEL1
(1)
1 Brown-out Detector trigger level 1 (unprogrammed)
BODLEVEL0
(1)
0 Brown-out Detector trigger level 1 (unprogrammed)
Note: 1. Please refer to Table. BODLEVEL Fuse Coding in System and Reset Characteristics for
BODLEVEL Fuse decoding.
Table 28-6. Fuse High Byte. (0x99)
High Fuse Byte Bit No. Description Default Value
OCDEN
(1)
7 Enable OCD 1 (unprogrammed, OCD disabled)
JTAGEN 6 Enable JTAG 0 (programmed, JTAG enabled)
SPIEN
(2)
5 Enable Serial Program and Data
Downloading
0 (programmed, SPI prog. enabled)
WDTON
(3)
4 Watchdog Timer Always On 1 (unprogrammed)
EESAVE 3 EEPROM memory is preserved
through the Chip Erase
1 (unprogrammed), EEPROM not
reserved
BOOTSZ1
(4)
2 Select Boot Size 0 (programmed)
BOOTSZ0
(4)
1 Select Boot Size 0 (programmed)
BOOTRST 0 Boot Reset vector Enabled 1 (unprogrammed)
Note:
1. Never ship a product with the OCDEN Fuse programmed regardless of the setting of Lock bits and
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.
2. The SPIEN Fuse is not accessible in serial programming mode.
3. Please refer to WDTCSR – Watchdog Timer Control Register for details.
4. The default value of BOOTSZ[1:0] results in maximum Boot Size. See Boot size configuration table
for details.
Table 28-7. Fuse High Byte.
High Fuse Byte Bit No. Description Default Value
RSTDISBL
(1)
7 External Reset Disable 1 (unprogrammed)
DWEN 6 debugWIRE Enable 1 (unprogrammed)
SPIEN
(2)
5 Enable Serial Program and Data
Downloading
0 (programmed, SPI programming
enabled)
WDTON
(3)
4 Watchdog Timer Always On 1 (unprogrammed)
Atmel ATmega644A [DATASHEET]
Atmel-42716C-ATmega644A_Datasheet_Complete-10/2016
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