ATxmega256A3BU Atmel Corporation, ATxmega256A3BU Datasheet - Page 368

• 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

28.16.3
28.16.4
8331A–AVR–07/11
REFCTRL – Reference Control register
EVCTRL – Event Control Register
• Bit 7 – Reserved
This bit is unused and reserved for future use. For compatibility with future devices, always write
this bit to zero when this register is written.
• Bits 6:4 – REFSEL[2:0]: ADC Reference Selection
These bits selects the reference for the ADC according to
Table 28-5.
• Bit 3:2 – Reserved
These bits are unused and reserved for future use. For compatibility with future devices, always
write these bits to zero when this register is written.
• Bit 1 – BANDGAP: Bandgap enable
Setting this bit enables the Bandgap for ADC measurement. Note that if any other functions are
using the Bandgap already, this bit does not need to be set when the internal 1.00V reference is
used in ADC or DAC, or if the Brown-out Detector is enabled.
• Bit 0 – TEMPREF: Temperature Reference enable
Setting this bit enables the temperature reference for ADC measurement.
• Bit 7:6 – SWEEP[1:0]: ADC Channel Sweep
These bits control which ADC channels are included in a channel sweep triggered by the event
system, or in free running mode. See
Bit
+0x02
Read/Write
Initial Value
Bit
+0x03
Read/Write
Initial Value
REFSEL[2:0]
101 - 111
000
001
010
011
100
R/W
R
7
–
0
7
0
ADC Reference selection
SWEEP[1:0]
R/W
R/W
6
0
6
0
Group Configuration
INT1V
INTVCC
AREFA
AREFB
INTVCC2
REFSEL[2:0]
R/W
R/W
5
0
5
0
Table 28-6 on page
EVSEL[2:0]
R/W
R/W
4
0
4
0
Description
10/11 of Bandgap (1.0V)
VCC/1.6
External reference from AREF pin on PORT A
External reference from AREF pin on PORT B
VCC/2
Reserved
R/W
Atmel AVR XMEGA AU
R
3
–
0
3
0
369.
Table 28-5 on page
R/W
R
2
–
0
2
0
BANDGAP
EVACT[2:0]
R/W
R/W
1
0
1
0
TEMPREF
368.
R/W
R/W
0
0
0
0
REFCTRL
EVCTRL
368