ATxmega256A3U Atmel Corporation, ATxmega256A3U Datasheet - Page 20

• Manufacturer Part Number: ATxmega256A3U
• Manufacturer: Atmel Corporation

Specifications of ATxmega256A3U

• 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: 50
• Ext Interrupts: 50
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 10
• Twi (i2c): 2
• Uart: 7
• 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

10.3.3
10.3.4
10.3.5
10.3.6
10.3.7
10.3.8
8386A–AVR–07/11
32.768kHz Crystal Oscillator
0.4 - 16MHz Crystal Oscillator
2MHz Run-time Calibrated Internal Oscillator
32MHz Run-time Calibrated Internal Oscillator
External Clock input
PLL with Multiplication factor 1 - 31x
A 32.768kHz crystal oscillator can be connected between TOSC1 and TOSC2 pins and enable a
dedicated low frequency oscillator input circuit. A low power mode with reduced voltage swing
on TOSC2 is available. This oscillator can be used as clock source for the System Clock, RTC
and as the DFLL reference clock.
The 0.4 - 16MHz Crystal Oscillator is a driver intended for driving both external resonators and
crystals ranging from 400kHz to 16MHz.
The 2MHz Run-time Calibrated Internal Oscillator is the default system clock source after reset.
It is calibrated during production to provide a default frequency which is close to its nominal fre-
quency. A Digital Frequency Looked Loop (DFLL) that can be enabled for automatic run-time
calibration of the oscillator to compensate for temperature and voltage drift to optimize the oscil-
lator accuracy.
The 32MHz Run-time Calibrated Internal Oscillator is a high frequency oscillator. It is calibrated
during production to provide a default frequency which is close to its nominal frequency. A DFLL
that can be enabled for automatic run-time calibration of the oscillator to compensate for temper-
ature and voltage drift to optimize the oscillator accuracy This oscillator can also be adjusted
and calibrated to any frequency between 30 and 55MHz.
The external clock input gives the possibility to connect a clock from an external source to
XTAL1.
The PLL provides the possibility of multiplying a frequency by any number from 1 to 31. In com-
bination with the prescalers, this gives a wide range of output frequencies from all clock sources.
XMEGA A3U
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