ATxmega256A3BU Atmel Corporation, ATxmega256A3BU Datasheet - Page 286

• 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

22.5
22.6
8331A–AVR–07/11
Data Modes
DMA Support
There are four combinations of SCK phase and polarity with respect to serial data. The SPI data
transfer formats are shown in
edges of the SCK signal, ensuring sufficient time for data signals to stabilize.
The leading edge is the first clock edge of a clock cycle. The trailing edge is the last clock edge
of a clock cycle.
Figure 22-2. SPI transfer modes.
DMA support on the SPI module is available only in slave mode. The SPI slave can trigger a
DMA transfer as one byte has been shifted into the DATA register. It is possible, however, to use
the XMEGA USART in SPI mode and then have DMA support in master mode. For details, refer
to
”USART in Master SPI Mode” on page
Mode 0
Mode 2
SAMPLE I
MOSI/MISO
CHANGE 0
MOSI PIN
CHANGE 0
MISO PIN
Mode 1
Mode 3
SAMPLE I
MOSI/MISO
CHANGE 0
MOSI PIN
CHANGE 0
MISO PIN
SS
SS
MSB first (DORD = 0)
LSB first (DORD = 1)
MSB first (DORD = 0)
LSB first (DORD = 1)
MSB
LSB
Figure
MSB
LSB
Bit 6
Bit 1
22-2. Data bits are shifted out and latched in on opposite
Bit 6
Bit 1
302.
Bit 5
Bit 2
Bit 5
Bit 2
Bit 4
Bit 3
Atmel AVR XMEGA AU
Bit 4
Bit 3
Bit 3
Bit 4
Bit 3
Bit 4
Bit 2
Bit 5
Bit 2
Bit 5
Bit 1
Bit 6
Bit 1
Bit 6
LSB
MSB
LSB
MSB
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