Datasheet

 2018 Microchip Technology Inc. Data Sheet Complete DS40002058A-page 47
ATxmega128A1U/ATxmega64A1U
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 controller 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 multi-
ple packets without software intervention. This reduces the CPU intervention 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.