ATxmega256A3BU Atmel Corporation, ATxmega256A3BU Datasheet - Page 234

• 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

20.3.3
8331A–AVR–07/11
OUT
The USB module then fetches endpoint Data Pointer register (DATAPTR) and waits for a
DATA0 packet. If a PID error or any other PID than DATA0 is detected, the USB module returns
to idle and waits for the next token packet.
The incoming data is written to the data buffer pointed to by the DATAPTR. If a bit-stuff error is
detected in the incoming data, the USB module returns to idle and waits for the next token
packet. If the number of received data bytes exceeds the endpoint's maximum data payload size
as specified by the Data Size (SIZE) in endpoint CTRL, the remainders of the received data
bytes are discarded. The packet will still be checked for bit-stuff and CRC errors. Software must
never report a maximum data payload size to the host that is greater than specified in SIZE. If
there was a bit-stuff or CRC error in the packet, the USB module returns to idle and waits for the
next token packet.
If data was successfully received, an ACK handshake is returned to the host, and the number of
received data bytes, excluding the CRC, is written to the endpoint Byte Counter (CNT). If the
number of received data bytes is the maximum data payload specified by SIZE, no CRC data
are written in the data buffer. If the number of received data is the maximum data payload spec-
ified by SIZE minus one, only the first CRC data bytes is written in the data buffer. If the number
of received databyte is equal or less than the data bytes payload specified by SIZE minus two,
the two CRC data bytes are written in the data buffer.
Finally, the Setup Transaction Complete Flag (SETUP), Data Buffer 0 Not Acknowledge Flag
(NACK0) and the Data Toggle Flag (TOGGLE) are set, while the remaining flags in the endpoint
Status register (STATUS) are cleared for both the addressed input and output endpoints. The
Setup Transaction Complete Interrupt Flag (SETUPIF) in INTFLAGSBCLR/SET is set. The
STALL in endpoint CTRL is cleared for both the addressed input and output endpoints.
When a SETUP token is detected and the device address of the token packet does not match
that of the endpoint, the packet is discarded and the USB module returns to idle and waits for the
next token packet.
When an OUT token is detected the, the USB module fetches endpoint CTRL and STATUS from
the addressed output endpoint in its endpoint configuration table. If the endpoint is disabled, the
USB module returns to idle and waits for the next token packet.
Atmel AVR XMEGA AU
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