AT90PWM81_14 Datasheet, PDF (23/327 Pages) ATMEL Corporation – Data and non-volatile program memory

AT90PWM81/161
Table 4-4. Fuse high byte.
High fuse byte
RSTDISBL ⁽¹⁾
Bit no.
7
Description
External reset disable
Default value
1 (unprogrammed)
DWEN
6
debugWIRE enable
1 (unprogrammed)
SPIEN ⁽²⁾
WDTON ⁽³⁾
5
Enable serial program and data
downloading
4
Watchdog timer always on
0 (programmed, SPI
programming enabled)
1 (unprogrammed)
EESAVE
3
EEPROM memory is preserved
through the chip erase
1 (unprogrammed), EEPROM
not reserved
BOOTSZ1
Select boot size
2
(see Table 20-7 on page 246 for
0 (programmed) ⁽⁴⁾
details)
BOOTSZ0
Select boot size
1
(see Table 20-7 on page 246 for
0 (programmed) ⁽⁴⁾
details)
BOOTRST
0
Select reset vector
1 (unprogrammed)
Notes:
1. See “Alternate Functions of Port E” on page 80 for description of RSTDISBL fuse.
2. The SPIEN Fuse is not accessible in serial programming mode.
3. See “Watchdog timer configuration.” on page 60 for details.
4. The default value of BOOTSZ1..0 results in maximum boot size.
Table 4-5. Fuse low byte.
Low fuse byte
CKDIV8 ⁽⁴⁾
CKOUT ⁽³⁾
Bit no.
7
6
Description
Divide clock by 8
Clock output
SUT1
5
Select start-up time
SUT0
4
Select start-up time
CKSEL3
3
Select clock source
CKSEL2
2
Select clock source
CKSEL1
1
Select clock source
CKSEL0
0
Select clock source
Default value
0 (programmed)
1 (unprogrammed)
1 (unprogrammed) ⁽¹⁾
0 (programmed) ⁽¹⁾
0 (programmed) ⁽²⁾
0 (programmed) ⁽²⁾
1 (unprogrammed) ⁽²⁾
0 (programmed) ⁽²⁾
Note: 1. The default value of SUT1..0 results in maximum start-up time for the default clock source.
See Table 5-4 on page 30 for details.
2. The default setting of CKSEL3..0 results in internal RC oscillator @ 8MHz. See Table 5-1 on
page 28 for details.
3. The CKOUT fuse allows the system clock to be output on PORTD0. See “Clock Output Buffer”
on page 34 for details.
4. See “System Clock Prescaler” on page 39 for details.
The status of the Fuse bits is not affected by Chip Erase. Note that the Fuse bits are locked if
Lock bit1 (LB1) is programmed. Program the Fuse bits before programming the Lock bits.
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