atmega32u4-16mu ATMEL Corporation, atmega32u4-16mu Datasheet - Page 367

• Manufacturer Part Number: atmega32u4-16mu
• Description: Atmega32u4 8-bit Avr Microcontroller With 32k Bytes Of Isp Flash And Usb Controller
• Manufacturer: ATMEL Corporation

7766A–AVR–03/08
Table 29-4.
Note:
Table 29-5.
Note:
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.
Fuse High Byte
OCDEN
JTAGEN
SPIEN
WDTON
EESAVE
BOOTSZ1
BOOTSZ0
BOOTRST
Fuse Low Byte
CKDIV8
CKOUT
SUT1
SUT0
CKSEL3
CKSEL2
CKSEL1
CKSEL0
(1)
1. The SPIEN Fuse is not accessible in serial programming mode.
2. The default value of BOOTSZ1..0 results in maximum Boot Size. See
3. See
4. Never ship a product with the OCDEN Fuse programmed regardless of the setting of Lock bits
1. The default value of SUT1..0 results in maximum start-up time for the default clock source.
2. The default setting of CKSEL3..0 results in internal RC Oscillator @ 8 MHz. See
3. The CKOUT Fuse allow the system clock to be output on PORTC7. See
4. See
(3)
(4)
(4)
(3)
for details.
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.
See
page 27
on page 36
Fuse High Byte
Fuse Low Byte
“Watchdog Timer” on page 53
Table 8-1 on page 48
“System Clock Prescaler” on page 36
Bit No
for details.
7
6
5
4
3
2
1
0
for details.
Bit No
7
6
5
4
3
2
1
0
Description
Enable OCD
Enable JTAG
Enable Serial Program and Data
Downloading
Watchdog Timer always on
EEPROM memory is preserved
through the Chip Erase
Select Boot Size (see
for details)
Select Boot Size (see
for details)
Select Bootloader Address as
Reset Vector
Description
Divide clock by 8
Clock output
Select start-up time
Select start-up time
Select Clock source
Select Clock source
Select Clock source
Select Clock source
for details.
for details.
Table 29-6
Table 29-6
for details.
Default Value
1 (unprogrammed, OCD
disabled)
0 (programmed, JTAG
enabled)
0 (programmed, SPI prog.
enabled)
1 (unprogrammed)
0 (programmed, EEPROM
preserved)
0 (programmed)
0 (programmed)
1 (unprogrammed, Reset
vector @0x0000)
Default Value
0 (programmed)
1 (unprogrammed)
1 (unprogrammed)
0 (programmed)
0 (programmed)
0 (programmed)
1 (unprogrammed)
0 (programmed)
ATmega32U4
Table 28-8 on page 364
(2)
(2)
(1)
(2)
(2)
(2)
“Clock Output Buffer”
(1)
(2)
Table 6-1 on
367