ATxmega128B1 Atmel Corporation, ATxmega128B1 Datasheet - Page 218

• Manufacturer Part Number: ATxmega128B1
• Manufacturer: Atmel Corporation

Specifications of ATxmega128B1

• Flash (kbytes): 128 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 53
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• Segment Lcd: 160
• 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
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 8
• Eeprom (bytes): 2048
• 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: 3
• Output Compare Channels: 10
• Input Capture Channels: 10
• Pwm Channels: 10
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

18.7
18.7.1
8291A–AVR–10/11
Multipacket Transfers
For Input Endpoints
Figure 18-8. Ping-pong operation overview.
Multipacket transfer enables a data payload exceeding the maximum data payload size of an
endpoint to be transferred as multiple packets without any software intervention. This reduces
interrupts and software intervention to the higher level USB transfer, and frees up significant
CPU time. Multipacket transfer is identical to the IN and OUT transactions described above,
unless otherwise noted in this section.
The application software provides the size and address of the SRAM buffer to be processed by
the USB module for a specific endpoint, and the USB module will then split the buffer in the
required USB data transfer.
Figure 18-9. Multipacket overview.
The total number of data bytes to be sent is written to CNT, as for normal operation. The auxil-
iary data register (AUXDATA) is used to store the number of bytes that will be sent, and must be
written to zero for a new transfer.
With multipacket
Without multipacket
With Ping-Pong
Without Ping-Pong
Transfer Complete Interrupt and data processing
USB data packet
Available time for data processing by CPU to avoid NACK
Atmel AVR XMEGA B
t
t
Double bank
single bank
Endpoint
Endpoint
Bank0
Bank1
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