at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 704

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

• DTGLE: Data Toggle
Read-only
0 = Identifies DATA0 packet.
1 = Identifies DATA1 packet.
Refer to Chapter 8 of the Universal Serial Bus Specification, Rev. 2.0 for more information on DATA0, DATA1 packet
definitions.
• EPEDS: Endpoint Enable Disable
Read:
0 = Endpoint disabled.
1 = Endpoint enabled.
Write:
0 = Disables endpoint.
1 = Enables endpoint.
Control endpoints are always enabled. Reading or writing this field has no effect on control endpoints.
Note: After reset, all endpoints are configured as control endpoints (zero).
• RXBYTECNT[10:0]: Number of Bytes Available in the FIFO
Read-only
When the host sends a data packet to the device, the USB device stores the data in the FIFO and notifies the microcontrol-
ler. The microcontroller can load the data from the FIFO by reading RXBYTECENT bytes in the UDP_FDRx register.
AT91SAM9G20 Preliminary
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6384B–ATARM–15-Dec-08