ATxmega256A3BU Atmel Corporation, ATxmega256A3BU Datasheet - Page 103

• Manufacturer Part Number: ATxmega256A3BU
• Manufacturer: Atmel Corporation

Specifications of ATxmega256A3BU

• Flash (kbytes): 256 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 47
• Ext Interrupts: 49
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 8
• Twi (i2c): 2
• Uart: 6
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 16
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 16
• Eeprom (bytes): 4096
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.6 to 3.6
• Operating Voltage (vcc): 1.6 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 7
• Output Compare Channels: 22
• Input Capture Channels: 22
• Pwm Channels: 22
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

8. Power Management and Sleep Modes
8.1
8.2
8.3
8331A–AVR–07/11
Features
Overview
Sleep Modes
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Various sleep modes and clock gating are provided in order to tailor power consumption to appli-
cation requirements. This enables the XMEGA microcontroller to stop unused modules to save
power.
All sleep modes are available and can be entered from active mode. In active mode, the CPU is
executing application code. When the device enters sleep mode, program execution is stopped
and interrupts or a reset is used to wake the device again. The application code decides which
sleep mode to enter and when. Interrupts from enabled peripherals and all enabled reset
sources can restore the microcontroller from sleep to active mode.
In addition, power reduction registers provide a method to stop the clock to individual peripherals
from software. When this is done, the current state of the peripheral is frozen, and there is no
power consumption from that peripheral. This reduces the power consumption in active mode
and idle sleep modes and enables much more fine-tuned power management than sleep modes
alone.
Sleep modes are used to shut down modules and clock domains in the microcontroller in order
to save power. XMEGA microcontrollers have five different sleep modes tuned to match the typ-
ical functional stages during application execution. A dedicated sleep instruction (SLEEP) is
available to enter sleep mode. Interrupts are used to wake the device from sleep, and the avail-
able interrupt wake-up sources are dependent on the configured sleep mode. When an enabled
interrupt occurs, the device will wake up and execute the interrupt service routine before con-
tinuing normal program execution from the first instruction after the SLEEP instruction. If other,
higher priority interrupts are pending when the wake-up occurs, their interrupt service routines
will be executed according to their priority before the interrupt service routine for the wake-up
interrupt is executed. After wake-up, the CPU is halted for four cycles before execution starts.
Power management for adjusting power consumption and functions
Five sleep modes
Power reduction register to disable clock and turn off unused peripherals in active and idle
modes
– Idle
– Power down
– Power save
– Standby
– Extended standby
Atmel AVR XMEGA AU
103