
NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
- 656 -
Revision V1.30
NUC97
0
T
E
CHNIC
A
L
RE
F
E
RE
N
CE
MA
NUA
L
USB 2.0 Device Controller (USBD)
5.22
5.22.1 Overview
The USB device controller interfaces the AHB bus and the UTMI bus. The USB controller contains
both the AHB master interface and AHB slave interface. CPU programs the USB controller registers
through the AHB slave interface. For IN or OUT transfer, the USB device controller needs to write data
to memory or read data from memory through the AHB master interface. The USB device controller is
complaint with USB 2.0 specification and it contains 12 configurable endpoints in addition to control
endpoint. These endpoints could be configured to BULK, INTERRUPT or ISO. The USB device
controller has a built-in DMA to relieve the load of CPU.
5.22.2 Features
USB Specification reversion 2.0 compliant
Supports 12 configurable endpoints in addition to Control Endpoint
Each of the endpoints can be Isochronous, Bulk or Interrupt and either IN or OUT direction
Three different operation modes of an in-endpoint
-
Auto Validation mode, Manual
Validation mode, Fly mode
Supports DMA operation
4096 Bytes Configurable RAM used as endpoint buffer
Supports Endpoint Maximum Packet Size up to 1024 bytes