Datasheet

300
8272E–AVR–04/2013
ATmega164A/PA/324A/PA/644A/PA/1284/P
Note: 1. The SPIEN Fuse is not accessible in serial programming mode.
2. The default value of BOOTSZ1..0 results in maximum Boot Size. See Table 26-10 on page
293 for details.
3. See ”WDTCSR – Watchdog Timer Control Register” on page 59 for details.
4. 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.
Note: 1. The default value of SUT1..0 results in maximum start-up time for the default clock source.
See ”” on page 337 for details.
2. The default setting of CKSEL3..0 results in internal RC Oscillator @ 8MHz. See Table 9-1 on
page 31 for details.
3. The CKOUT Fuse allow the system clock to be output on PORTB1. See ”Clock Output Buffer”
on page 39 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.
Table 27-4. Fuse High byte.
Fuse High byte Bit no. Description Default value
OCDEN
(4)
7Enable OCD
1 (unprogrammed, OCD
disabled)
JTAGEN 6 Enable JTAG 0 (programmed, JTAG enabled)
SPIEN
(1)
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 preserved)
BOOTSZ1 2
Select Boot Size (see Table 27-9 on
page 303 for details)
0 (programmed)
(2)
BOOTSZ0 1
Select Boot Size (see Table 27-9 on
page 303 for details)
0 (programmed)
(2)
BOOTRST 0 Select Reset Vector 1 (unprogrammed)
Table 27-5. Fuse Low byte.
Fuse Low byte Bit no. Description Default value
CKDIV8
(4)
7 Divide clock by 8 0 (programmed)
CKOUT
(3)
6 Clock output 1 (unprogrammed)
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)
CKSEL1 1 Select Clock source 1 (unprogrammed)
(2)
CKSEL0 0 Select Clock source 0 (programmed)
(2)