ATxmega256A3 Atmel Corporation, ATxmega256A3 Datasheet - Page 320

• Manufacturer Part Number: ATxmega256A3
• Manufacturer: Atmel Corporation

Specifications of ATxmega256A3

• 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 Speed: No
• Usb Interface: No
• 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

26.10 Register Description
26.10.1
26.10.2
8077H–AVR–12/09
CTRLA – DAC Control Register A
CTRLB – DAC Control Register B
The calibration of the DAC adjust the offset and gain. To calibrate offset you can output mid
code and adjust the offset calibration until you get ~0 LSB offset The gain is adjusted around mid
code so it should not affect the offset calibration if you read the output at mid code and max (or
min code) and adjust the calibration values until you get ~0 LSB gain.
• Bits 7:5 - 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 4 - IDOEN: DAC Internal Output Enable
Setting this bit routs the internal DAC output to the ADC and Analog Comparator MUXes.
• Bit 3 - CH1EN: DAC Channel 1 Output Enable
Setting this bit will make channel 1 available on pin while clearing the bit makes channel 1 only
available for internal use.
• Bit 2 - CH0EN: DAC Channel 0 Output Enable
Setting this bit will make channel 0 available on pin while clearing the bit makes channel 0 only
available for internal use.
• Bit 1 - Res - 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.
• Bit 0 - ENABLE: DAC Enable
This bit enables the entire DAC.
• 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 6:5 - CHSEL[1:0]: DAC Channel Selection
These bits control wether the DAC should operate with single or dual channel outputs.
1
Bit
+0x00
Read/Write
Initial Value
Bit
+0x01
Read/Write
Initial Value
shows the available selections.
R
7
0
-
7
R
0
-
R/W
R
6
0
-
6
0
CHSEL[1:0]
R
5
0
-
R
5
0
IDOEN
R/W
4
0
R
4
0
-
CH1EN
R
3
0
R
3
0
-
CH0EN
R/W
2
0
R
2
0
-
CH1TRIG
R/W
R/W
1
0
1
0
.
XMEGA A
CH0TRIG
ENABLE
R/W
R/W
0
0
0
0
Table 26-
CTRLA
CTRLB
320