ATxmega32A4 Atmel Corporation, ATxmega32A4 Datasheet - Page 112

• Manufacturer Part Number: ATxmega32A4
• Manufacturer: Atmel Corporation

Specifications of ATxmega32A4

• Flash (kbytes): 32 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 34
• Ext Interrupts: 34
• Usb Speed: No
• Usb Interface: No
• Spi: 7
• Twi (i2c): 2
• Uart: 5
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 2
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 4
• Eeprom (bytes): 1024
• 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: 5
• Output Compare Channels: 16
• Input Capture Channels: 16
• Pwm Channels: 16
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

10.3
10.3.1
8077H–AVR–12/09
Battery Backup Module
Battery Backup Power-On Detection
Figure 10-1. Battery Backup Module and its power domain implementation
The Battery Backup Module consists of the following:
• A V
• A Power-switch for switching power to the battery backup domain between main power and the
• A 32.768 kHz Crystal Oscillator (XOSC) with 32.768 kHz, 1.024 kHz and 1 Hz output.
• A XOSC Failure Monitor for detecting failure on the Crystal Oscillator.
• A 32-bit Real Time Counter.
• Two Battery Backup registers.
The main BOD is used to detect Brown-Out on the main power so this must be enabled for the
power switching to work.
When main BOD is detected, the Battery Backup Module will switch to be powered from the V
pin. When main power is restored and/or the device is reset, software must enable access to the
Battery Backup Module by writing a dedicated Access Enable bit in the module.
The Battery Backup Power-On Detection circuit will set the POD Flag (BBPODF) when power is
connected to the V
TOSC1
TOSC2
VBAT
backup battery power domain. It includes
V
BAT
– A Battery Backup Power-On Detector (BBPOD).
– A sampled Battery Backup Brown-Out Detector (BBBOD).
BAT
pin.
power supervisor that ensures correct operation and detection of falling power in the
supervisor
power
V
BAT
BAT
Registers
monitor
Backup
XOSC
XOSC
RTC
pin.
Power
switch
Programming
Watchdog w/
independent
Internal
Interface
RCOSC
OCD &
RAM
Peripherals
&
CPU
EEPROM
& Fuses
supervision
Oscillator &
FLASH,
controller
power
sleep
Main
XMEGA A
XTAL1
XTAL2
VCC
GPIO
112
BAT