ATxmega128B1 Atmel Corporation, ATxmega128B1 Datasheet - Page 79

• Manufacturer Part Number: ATxmega128B1
• Manufacturer: Atmel Corporation

Specifications of ATxmega128B1

• Flash (kbytes): 128 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 53
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• Segment Lcd: 160
• 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
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 8
• Eeprom (bytes): 2048
• 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: 3
• Output Compare Channels: 10
• Input Capture Channels: 10
• Pwm Channels: 10
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

7.4.1.2
7.4.1.3
7.4.1.4
7.4.2
7.4.2.1
7.4.2.2
8291A–AVR–10/11
External Clock Sources
32.768kHz Calibrated Oscillator
32MHz Run-time Calibrated Oscillator
2MHz Run-time Calibrated Oscillator
External Clock Input
0.4MHz - 16MHz Crystal Oscillator
This oscillator provides an approximate 32.768kHz clock. It is calibrated during production to
provide a default frequency close to its nominal frequency. The calibration register can also be
written from software for run-time calibration of the oscillator frequency. The oscillator employs a
built-in prescaler, which provides both a 32.768kHz output and a 1.024kHz output.
The 32MHz run-time calibrated internal oscillator is a high-requency oscillator. It is calibrated
during production to provide a default frequency close to its nominal frequency. A digital fre-
quency looked loop (DFLL) can be enabled for automatic run-time calibration of the oscillator to
compensate for temperature and voltage drift and optimize the oscillator accuracy. This oscilla-
tor can also be adjusted and calibrated to any frequency between 30MHz and 55MHz. The
production signature row contains 48MHz calibration values intended used when the oscillator is
used a full-speed USB clock source.
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 close to its nominal frequency. A
DFLL can be enabled for automatic run-time calibration of the oscillator to compensate for tem-
perature and voltage drift and optimize the oscillator accuracy.
The XTAL1 and XTAL2 pins can be used to drive an external oscillator, either a quartz crystal or
a ceramic resonator. XTAL1 can be used as input for an external clock signal. The TOSC1 and
TOSC2 pins is dedicated to driving a 32.768kHz crystal oscillator.
This oscillator can operate in four different modes optimized for different frequency ranges, all
within 0.4MHz - 16MHz.
resonator.
Figure 7-2.
Two capacitors, C1 and C2, may be added to match the required load capacitance for the con-
nected crystal.
To drive the device from an external clock source, XTAL1 pin or any pin of PORTC can be used.
XTAL1 must be driven as shown in
a general I/O pin.
Crystal oscillator connection.
Figure 7-2
Figure 7-3 on page
shows a typical connection of a crystal oscillator or
C1
C2
Atmel AVR XMEGA B
80. In this mode, XTAL2 can be used as
XTAL2
XTAL1
GND
79