Datasheet

227
ATtiny828 [DATASHEET]
8371A–AVR–08/12
Table 90. High Fuse Byte
Notes: 1. Programming this fuse bit will change the functionality of the RESET pin and render further programming via
the serial interface impossible. The fuse bit can be unprogrammed using the parallel programming algorithm
(see page 232).
2. This fuse bit is not accessible in serial programming mode.
3. This setting enables SPI programming.
4. This setting does not preserve EEPROM.
Table 91. Low Fuse Byte
Note: 1. Unprogramming this fuse at low voltages may result in overclocking. See Section 24.3 on page 249 for
device speed versus supply voltage.
2. This setting results in maximum start-up time for the default clock source.
3 – – 1 (unprogrammed)
2 BOOTSZ1
Sets size of boot loader section Page 216
1 (unprogrammed)
1 BOOTSZ0 1 (unprogrammed)
0 BOOTRST Defines boot reset vector Page 216 1 (unprogrammed)
Bit # Bit Name Use See Default Value
7 RSTDISBL Disables external reset
(1)
Page 79 1 (unprogrammed)
6 DWEN Enables debugWIRE
(1)
Page 212 1 (unprogrammed)
5 SPIEN
Enables serial programming and
downloading of data to device
(2)
0 (programmed)
(3)
4 WDTON Sets watchdog timer permanently on Page 46 1 (unprogrammed)
3 EESAVE
Preserves EEPROM memory during Chip
Erase operation
Page 235 1 (unprogrammed)
(4)
2 BODLEVEL2
Sets BOD trigger level Page 251
1 (unprogrammed)
1 BODLEVEL1 1 (unprogrammed)
0 BODLEVEL0 1 (unprogrammed)
Bit # Bit Name Use See Default Value
7 CKDIV8 Divides clock by 8
(1)
Page 30 0 (programmed)
6 CKOUT Outputs system clock on port pin Page 30 1 (unprogrammed)
5 SUT1
Sets system start-up time Page 30
1 (unprogrammed)
(2)
4 SUT0 0 (programmed)
(2)
3 – – 1 (unprogrammed)
2 – – 1 (unprogrammed)
1 CKSEL1
Selects clock source Page 28
1 (unprogrammed)
(3)
0 CKSEL0 0 (programmed)
(3)
Bit # Bit Name Use See Default Value