![](http://datasheet.mmic.net.cn/230000/W722_datasheet_15631126/W722_10.png)
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W722 USB Hub/Compound Device Controller
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Oki Semiconductor
FUNCTIONAL DESCRIPTION
The W722 provides Oki’s SIE, a HCC, a HR, and a status/descriptor/register file block in four highly
integrated submodules. The submodule partitioning allows custom configurations to be easily devel-
oped. Oki also offers optional USB FIFO Controller and Application Interface Logic Modules to form a
USB Compound Device function.
Serial Interface Engine
Oki’s SIE handles the USB communication protocol and performs:
Clock generation
Packet sequencing
Signal generation/detection
CRC generation/checking
Bit-stuffing
PacketID generation/decoding
When the W722 is in a compound device application, the Oki SIE can be shared by both the Hub function
and the embedded function.
Core Controller
The HCC includes:
A request parser to interpret the host requests/tokens to both the default Endpoint 0 and the Status
Change Endpoint 1.
A (DMA) controller/pointer block, which is capable of handling aborts and retries, to handle data
movement from/to the status descriptor memory and the register file.
A parallel read/write interface to a customer’s microcontroller.
Optional control state machines to execute requests, respond to tokens, and handle errors if
customers choose not to use a microcontroller.
Repeater
The HR includes:
Repeater logic to manage connectivity on a per packet basis. It can handle any combination of full-
speed and low-speed devices at the downstream ports. It also supports exception handling, such as
fault recovery, suspend/resume as directed by the Host, and remote-wakeup and Frame timer
synchronization.
Four-port state machines which can interpret and respond to bus events, such as
connect/disconnect detection, port enable/disable, suspend/resume, reset, and power switching.
The power manager and central clocking circuitry.
Port State Machine
The port state machine logic can be implemented as an external port, or an internal port for communica-
tion with an embedded function. To expand the Hub Megamacro function, additional port state machine
functional blocks can be added.