Datasheet

159
ATtiny2313/V
2543H–AVR–02/05
Fuse Bits The ATtiny2313 has three Fuse bytes. Table 67 and Table 68 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.
Note: 1. The SPIEN Fuse is not accessible in serial programming mode.
2. See “Watchdog Timer Control Register - WDTCSR” on page 41 for details.
3. Never ship a product with the DWEN Fuse programmed regardless of the setting of
Lock bits. A programmed DWEN Fuse enables some parts of the clock system to be
running in all sleep modes. This may increase the power consumption.
4. See Table 16 on page 34 for BODLEVEL Fuse decoding.
5. See “Alternate Functions of Port A” on page 52 for description of RSTDISBL Fuse.
Table 66. Fuse Extended Byte
Fuse Extended
Byte
Bit
No Description Default Value
7 – 1 (unprogrammed)
6 – 1 (unprogrammed)
5 – 1 (unprogrammed)
4 – 1 (unprogrammed)
3 – 1 (unprogrammed)
2 – 1 (unprogrammed)
1 – 1 (unprogrammed)
SELFPRGEN 0 Self Programming Enable 1 (unprogrammed)
Table 67. Fuse High Byte
Fuse High Byte
Bit
No Description Default Value
DWEN
(3)
7 debugWIRE Enable 1 (unprogrammed)
EESAVE 6
EEPROM memory is preserved
through the Chip Erase
1 (unprogrammed, EEPROM
not preserved)
SPIEN
(1)
5
Enable Serial Program and Data
Downloading
0 (programmed, SPI prog.
enabled)
WDTON
(2)
4 Watchdog Timer always on 1 (unprogrammed)
BODLEVEL2
(4)
3 Brown-out Detector trigger level 1 (unprogrammed)
BODLEVEL1
(4)
2 Brown-out Detector trigger level 1 (unprogrammed)
BODLEVEL0
(4)
1 Brown-out Detector trigger level 1 (unprogrammed)
RSTDISBL
(5)
0 External Reset disable 1 (unprogrammed)