MEDIATEK Ralink MT7620 - USB Device Controller

PGMT7620_V.1.0_040503
Page 186 of 523
MT7620 PROGRAMMING GUIDE
Integrated 802.11n MAC/BBP and 2.4 GHz RF/FEM Router-on-a-Chip
2.18 USB Device Controller
2.18.1 Features
 Supports the USB 2.0 Specification (Revision 1.0a), operates in High-Speed (HS, 480 Mbps)
 Supports up to 2 bulk-in and 2 bulk-out endpoints, and including control endpoint 0.
 Packet DMA (PDMA) is integrated for efficient data transfer.
 Supports bulk-out aggregation features. More than one packet can be aggregated to single bulk transfer.
 Supports two Rx descriptor rings and two Tx descriptor rings for QoS service.
2.18.2 Block Diagram
Asynch Tx
Asynch Rx
OUTFIFO
INTFIFO
HOST_IF
UDMA_TXFSM
WRR_SCH
UDMA_RXFSM
PDMA_TX
OUT EP 1
OUT EP 2
IN EP 1
IN EP 2
Asynch
Control
PDMA_RX
WRR_SCH
USB Bus
USB Clock DomainSoC Clock Domain
PBus
RBus
Rx Ring #0
Rx Ring #1
Tx Ring #0
Tx Ring #1
Figure 2-19 USB Device Controller Block Diagram
2.18.3 Bulk Out
USB device core supports two modes in BULK_OUT direction. These are aggregation mode and legacy mode,
and are controlled by register EPOUT_AGGEN (UDMA_CTRL[20:16]).