Figure 4-18 shows the functional block diagram of the USB 2.0 subsystem (USB2SS), which includes a wrapper module, a USB controller module, a PHY module, external interfaces, and internal interfaces.
Figure 13-149 USB 2.0
Subsystem (USB2SS) Functional Block Diagram
- The USB Core with a Dual-Role-Device Controller module and internal RAMs:
- Compatible to the xHCI 1.0 standard in Host
mode
- xHCI 0.96 backwards compatibility mode available
- Support for either USB Host or USB Device
modes
- High-Speed (HS, 480Mbps) and Full-Speed (FS, 12Mbps) are offered
for both Host and Device modes. Low-Speed (LS, 1.5Mbps) is only
supported for Host mode.
- Internal DMA controller for high-bandwidth, low overhead data transfer
- Three local RAMs supporting:
- Descriptor caching and data pre-fetching for high performance
- 2176 words of RAM0 for DCACHE
- Dynamic Tx/Rx FIFO memory allocation for all
EPs
- 5888 words of RAM1 for TX FIFOs
- 832 words of RAM2 for RX FIFOs
- Supports all transfer types - Control, Bulk, Interrupt, and Isochronous
- Supports high-bandwidth ISO mode
- Supports 15 IN, 15 OUT endpoints (EPs), and one EP0 endpoint which is bidirectional
- The integrated USB PHY module:
- A USB2 PHY connected to the core via internal UTMI+ port
- External interfaces (towards device boundary):
- To USB Connector:
- DP/DM - a bidirectional signal pair for HS, FS, LS mode operation
- To an external Charge Pump for VBUS 5V generation:
- DRVVBUS - an active high output that controls an external 5V charge pump. The core uses this output to automatically ensure that VBUS has 5V supplied by the charge pump during Host mode operation.
- Internal interface (towards internal system):
- An OCP secondary interface for MMR transactions
to/from the controller.
- An OCP secondary interface for MMR transactions
to/from the PHY.
- An AXI primary interface for high-bandwidth DMA
transactions.
- Interrupt interface:
- USB_MAINn_INT[3:0] - 4 programmable interrupts associated with DMA traffic
- USB_MISCINT - single interrupt line for misc events