USB System Architecture

Table B-5: Format of Hub Status Fields Returned During the Get Hub Status Request

Hub State Change Fields

Two bit fields are defined within the hub state change fields as shown in Table B-6:

•Local Power Status Change

•Over-Current Indicator Change

Local Power Status Change

This field corresponds directly to the local power status bit that reports the current status of local power. If the local power status bit is implemented, then this bit must also be implemented and vice versa. This corresponding change bit indicates whether or not there has been a change in the local power since last acknowledged. The bit definition is:

•0 = No change has occurred to local power status

•1 = Local power status has changed

If this bit is set then the local power status can be checked to determine the current state of the local power.

Over-Current Indicator Change

This bit field corresponds to the over-current indicator bit and must also be implemented if the over-current indicator bit is implemented and vice versa. The bit definition is:

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