ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 382

• 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

Table 29-2.
Notes:
7766F–AVR–11/10
Symbol
t
t
t
t
t
t
HIGH
SU;STA
HD;DAT
SU;DAT
SU;STO
BUF
1. In ATmega16U4/ATmega32U4, this parameter is characterized and not 100% tested.
2. Required only for f
3. C
4. f
5. This requirement applies to all ATmega16U4/ATmega32U4 2-wire Serial Interface operation. Other devices connected to the
6. The actual low period generated by the ATmega16U4/ATmega32U4 2-wire Serial Interface is (1/f
7. The actual low period generated by the ATmega16U4/ATmega32U4 2-wire Serial Interface is (1/f
2-wire Serial Bus need only obey the general f
be greater than 6 MHz for the low time requirement to be strictly met at f
time requirement will not be strictly met for f
nected to the bus may communicate at full speed (400 kHz) with other ATmega16U4/ATmega32U4 devices, as well as any
other device with a proper t
Parameter
High period of the SCL clock
Set-up time for a repeated START condition
Data hold time
Data setup time
Setup time for STOP condition
Bus free time between a STOP and START
condition
CK
b
= capacitance of one bus line in pF.
= CPU clock frequency
2-wire Serial Bus Requirements (Continued)
Figure 29-3. 2-wire Serial Bus Timing
SCL
> 100 kHz.
SCL
SDA
LOW
t
SU;STA
acceptance margin.
SCL
SCL
t
HD;STA
> 308 kHz when f
t
t
of
requirement.
LOW
f
f
f
f
f
f
f
f
f
f
f
f
SCL
SCL
SCL
SCL
SCL
SCL
SCL
SCL
SCL
SCL
SCL
SCL
Condition
t
HIGH
≤ 100 kHz
> 100 kHz
≤ 100 kHz
> 100 kHz
≤ 100 kHz
> 100 kHz
≤ 100 kHz
> 100 kHz
≤ 100 kHz
> 100 kHz
≤ 100 kHz
> 100 kHz
t
HD;DAT
CK
= 8 MHz. Still, ATmega16U4/ATmega32U4 devices con-
t
LOW
SCL
= 100 kHz.
t
SU;DAT
250
100
Min
4.0
0.6
4.7
0.6
4.0
0.6
4.7
1.3
0
0
ATmega16/32U4
SCL
SCL
t
- 2/f
- 2/f
SU;STO
t
CK
CK
r
3.45
Max
0.9
–
–
–
–
–
–
–
–
–
–
), thus f
), thus the low
t
CK
BUF
Units
must
µs
µs
µs
µs
µs
µs
ns
ns
µs
µs
µs
µs
382