ATxmega256A3BU Atmel Corporation, ATxmega256A3BU Datasheet - Page 367

• 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

8331A–AVR–07/11
Table 28-2.
• Bit 6:5 – CURRLIMIT[1:0]: Current Limitation
These bits can be used to limit the maximum current consumption of the ADC. Setting these bits
will also reduce the maximum sampling rate. The available settings is shown in
page
actual current limitation for each setting.
Table 28-3.
• Bit 4 – CONVMODE: ADC Conversion Mode
This bit controls whether the ADC will work in signed or unsigned mode. By default this bit is
cleared and the ADC is configured for unsigned mode. When this bit is set the ADC is configured
for signed mode.
• Bit 3 – FREERUN: ADC Free Running Mode
When the bit is set to one, the ADC is in free running mode and ADC channels defined in the
EVCTRL register are swept repeatedly.
• Bit 2:1 – RESOLUTION[1:0]: ADC Conversion Result Resolution
These bits define whether the ADC completes the conversion at 12- or 8-bit result. They also
define whether the 12-bit result is left or right oriented in the 16-bit result registers. See
28-4 on page 367
Table 28-4.
• Bit 0 - 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.
IMPMODE
RESOLUTION[1:0]
CURRLIMIT[1:0]
367. The indicated current limitations are nominal values, refer to device datasheet for
0
1
00
01
10
11
00
01
10
11
Gain Stage Impedence Mode
ADC Current Limitations
ADC Conversion Result resolution
HIGHIMP
LOWIMP
for possible settings.
Group Configuration
Group Configuration
NO
LOW
MED
HIGH
Group Configuration
12BIT
8BIT
LEFT12BIT
Description
For high-impedance sources. Charge will remain on input
For low impedance sources
12-bit result, right adjusted
Reserved
8-bit result, right adjusted
12-bit result, left adjusted
Description
No currentlimit
Low current limit, max sampling rate 1.5MSPS
Medium current limit, max sampling rate 1MSPS
High current limit, max sampling rate 0.5MSPS
Description
Atmel AVR XMEGA AU
Table 28-3 on
Table
367