The USB 2.0 subsystem, supports the following USB features:
- Operational modes:
- Supports USB 2.0 Host mode at High-Speed (HS,
480Mbps), Full-Speed (FS, 12Mbps), and
Low-Speed (LS,
1.5Mbps) - Supports USB 2.0 Device mode at High-Speed (HS,
480Mbps), and Full-Speed (FS, 12Mbps). Low-Speed
is not supported in Device mode.
- Supports all modes of transfers - Control, Bulk, Interrupt, and Isochronous.
- A DRD (Dual-Role-Device - Host or Device) USB controller with the following features:
- Compatible to the xHCI 1.0 specification in Host
mode with xHCI 0.96 backwards compatibility
mode
- Compatible with the USB 2.0 specification in Device mode
- Supports 15 IN (Receive), 15 OUT (Transmit) endpoints (EPs), and one EP0 endpoint which is bidirectional
- Internal DMA controller
- Descriptor caching and data pre-fetching ensures high performance
- Dynamic FIFO memory allocation for all endpoints
- Operation flexibility
- Same programming model for HS, FS, and LS operation
- The controller can provide either USB Host or USB
Device functionality
- Multiple interrupt lines:
- Four programmable interrupts
- A MISC interrupt line for all miscellaneous events
- External requirements:
- Needs an external Charge Pump for VBUS 5V
generation in Host mode. (Device mode does not
require VBUS generation).