ATXMEGA128B3-AU ATMEL [ATMEL Corporation], ATXMEGA128B3-AU Datasheet - Page 42

• Manufacturer Part Number: ATXMEGA128B3-AU
• Description: 8/16-bit Atmel XMEGA B3 Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

XMEGA B3
the configuration of these. The USB module has built-in direct memory access (DMA), and will
read/write data from/to the SRAM when a USB transaction takes place.
To maximize throughput, an endpoint address can be configured for ping-pong operation. When
done, the input and output endpoints are both used in the same direction. The CPU or DMA con-
troller can then read/write one data buffer while the USB module writes/reads the others, and
vice versa. This gives double buffered communication.
Multipacket transfer enables a data payload exceeding the maximum packet size of an endpoint
to be transferred as multiple packets without software intervention. This reduces the CPU inter-
vention and the interrupts needed for USB transfers.
For low-power operation, the USB module can put the microcontroller into any sleep mode when
the USB bus is idle and a suspend condition is given. Upon bus resumes, the USB module can
wake up the microcontroller from any sleep mode.
PORTD has one USB. Notation of this is USB.
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