ATxmega128A4U Atmel Corporation, ATxmega128A4U Datasheet - Page 140

• Manufacturer Part Number: ATxmega128A4U
• Manufacturer: Atmel Corporation

Specifications of ATxmega128A4U

• Flash (kbytes): 128 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 34
• Ext Interrupts: 34
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• 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): 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: 5
• Output Compare Channels: 16
• Input Capture Channels: 16
• Pwm Channels: 16
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

13.3
8331A–AVR–07/11
I/O Pin Use and Configuration
Figure 13-1 on page 140
controlling a pin.
Figure 13-1. General I/O pin functionality.
Each port has one data direction (DIR) register and one data output value (OUT) register that
are used for port pin control. The data input value (IN) register is used for reading the port pins.
In addition, each pin has a pin configuration (PINnCTRL) register for additional pin configuration.
Direction of the pin is decided by the DIRn bit in the DIR register. If DIRn is written to one, pin n
is configured as an output pin. If DIRn is written to zero, pin n is configured as an input pin.
When direction is set as output, the OUTn bit in OUT is used to set the value of the pin. If OUTn
is written to one, pin n is driven high. If OUTn is written to zero, pin n is driven low.
The IN register is used for reading pin values. A pin value can always be read regardless of
whether the pin is configured as input or output, except if digital input is disabled.
The I/O pins are tri-stated when a reset condition becomes active, even if no clocks are running.
shows the I/O pin functionality and the registers that are available for
Atmel AVR XMEGA AU
140