Industrial Temperature Rated USB 2.0 High-Speed 2-Port Hub Controller

Datasheet

1

7

 

1

1

8

 

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S

Slave Address

Wr

A

Register Address

 

A

...

 

 

 

 

 

 

 

 

 

 

 

 

8

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Byte Count = N A

Data byte 1

A

Data byte 2

A

 

Data byte N

A

P

Block WriteFigure 4.1 Block Write

Block Read

A Block Read differs from a block write in that the repeated start condition exists to satisfy the I2C specification’s requirement for a change in the transfer direction.

 

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Slave Address

Wr

 

 

 

Register Address

 

 

 

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Slave Address

 

Rd

 

A

 

 

A

 

 

 

A

...

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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A

 

 

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P

 

Byte Count = N

 

Data byte 1

 

Data byte 2

 

 

 

 

Data byte N

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Block ReadFigure 4.2 Block Read

4.3.2Invalid Protocol Response Behavior

Registers that are accessed with an invalid protocol are not updated. A register is only updated following a valid protocol. The only valid protocols are Write Block and Read Block, which are described above.

The Hub only responds to the hardware selected Slave Address.

Attempting to communicate with the Hub over SMBus with an invalid slave address or invalid protocol results in no response, and the SMBus Slave Interface returns to the idle state.

The only valid registers that are accessible by the SMBus slave address are the registers defined in the Registers Section. See Section 4.3.3 for the response to undefined registers.

4.3.3General Call Address Response

The Hub does not respond to a general call address of 0000_000b.

4.3.4Slave Device Time-Out

According to the SMBus Specification, V1.0 devices in a transfer can abort the transfer in progress

and release the bus when any single clock low interval exceeds 25ms (TTIMEOUT, MIN). Devices that have detected this condition must reset their communication and be able to receive a new START

condition no later than 35ms (TTIMEOUT, MAX).

Note: Some simple devices do not contain a clock low drive circuit; this simple kind of device typically resets its communications port after a start or stop condition. The Slave Device Time-Out must be implemented.

Revision 1.92 (11-28-07)

26

SMSC USB2512i

 

DATASHEET