ATmega32U2 Atmel Corporation, ATmega32U2 Datasheet - Page 42

• Manufacturer Part Number: ATmega32U2
• Manufacturer: Atmel Corporation

Specifications of ATmega32U2

• Flash (kbytes): 32 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 22
• Ext Interrupts: 20
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 1
• 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: 2
• Output Compare Channels: 5
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

9. Power Management and Sleep Modes
9.1
9.2
9.3
7799D–AVR–11/10
Overview
Sleep Modes
Idle Mode
Sleep modes enable the application to shut down unused modules in the MCU, thereby saving
power. The AVR provides various sleep modes allowing the user to tailor the power consump-
tion to the application’s requirements.
Figure 8-1 on page 26
their distribution. The figure is helpful in selecting an appropriate sleep mode. shows the differ-
ent sleep modes and their wake up sources.
Table 9-1.
Notes:
To enter any of the five sleep modes, the SE bit in SMCR must be written to logic one and a
SLEEP instruction must be executed. The SM2, SM1, and SM0 bits in the SMCR Register select
which sleep mode (Idle, Power-down, Power-save, Standby or Extended standby) will be acti-
vated by the SLEEP instruction. See
If an enabled interrupt occurs while the MCU is in a sleep mode, the MCU wakes up. The MCU
is then halted for four cycles in addition to the start-up time, executes the interrupt routine, and
resumes execution from the instruction following SLEEP. The contents of the Register File and
SRAM are unaltered when the device wakes up from sleep. If a reset occurs during sleep mode,
the MCU wakes up and executes from the Reset Vector.
When the SM2:0 bits are written to 000, the SLEEP instruction makes the MCU enter Idle mode,
stopping the CPU but allowing the USB, SPI, USART, Analog Comparator, Timer/Counters,
Sleep Mode
Idle
Power-down
Power-save
Standby
Extended
Standby
1. Only recommended with external crystal or resonator selected as clock source.
2. For INT[7:4], only level interrupt.
3. Asynchronous USB interrupt is WAKEUPI only.
(1)
Active Clock Domains and Wake-up Sources in the Different Sleep Modes.
Active Clock
Domains
presents the different clock systems in the ATmega8U2/16U2/32U2, and
X
Table 9-2
Oscillators
X
X
X
for a summary.
ATmega8U2/16U2/32U2
X
X
X
X
X
(2)
(2)
(2)
(2)
X
Wake-up Sources
X
X
X
X
X
X
X
X
X
X
X
X
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