ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 348

• Manufacturer Part Number: ATmega32U4
• Manufacturer: Atmel Corporation

Specifications of ATmega32U4

• Flash (kbytes): 32 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 14
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 26
• Ext Interrupts: 13
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 3.3
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 12
• Input Capture Channels: 2
• Pwm Channels: 8
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

7766F–AVR–11/10
Table 28-4.
Note:
Table 28-5.
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 setting of CKSEL3..0 results in Low Power Crystal Oscillator for ATmega16U4 and
2. The CKOUT Fuse allow the system clock to be output on PORTC7. See
3. See
(2)
(4)
(3)
(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.
ATmega32U4, and Internal RC oscillator for ATmega16U4RC and ATmega32U4RC. See
Table 6-1 on page 28
on page 37
Fuse High Byte
Fuse Low Byte
“Watchdog Timer” on page 55
“System Clock Prescaler” on page 37
Bit Nr
7
6
5
4
3
2
1
0
for details.
Bit No
7
6
5
4
3
2
1
0
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.
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
for details.
ATmega16U4/32U4
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
0 (programmed)
for details.
Table 28-7
Table 28-7
1 (unprogrammed)
1 (unprogrammed)
(1)
0 (programmed)
0 (programmed)
ATmega16/32U4
Default Value
(1)
(1)
(1)
Default Value
1 (unprogrammed, OCD
disabled)
0 (programmed, JTAG
enabled)
0 (programmed, SPI prog.
enabled)
1 (unprogrammed)
1 (unprogrammed, EEPROM
preserved)
0 (programmed)
0 (programmed)
1 (unprogrammed, Reset
vector @0x0000)
ATmega16U4RC/32U4RC
0 (programmed)
0 (programmed)
1 (unprogrammed)
0 (programmed)
Table 27-8 on page 344
“Clock Output Buffer”
(2)
(2)
(1)
(1)
(1)
(1)
348