Philips Semiconductors

Product specification

PDIUSBH11

Universal Serial Bus Hub

1997 Aug 01

15

Set Status Change Bits

Command

: F7h

Data

: Write 1 byte

For assembling the hub’s status change register, the device needs some additional information from the controller, i.e. the Local Power Status

Change bit and the embedded function Status Change bit.

These are provided by the Set Status Change Bits command. This command is always followed by one data write which contains the Local

Power Status Change bit at the LSB and the embedded function Status Change bit at position 1. All other bits should be 0.

X

7

X

6

X

5

X

4

X

3

X

2

0

1

0

0

POWER ON VALUE

LOCAL POWER

EMBEDDED FUNCTION

RESERVED

SV00511

GENERAL COMMANDS

Send Resume

Command

: F6h

Data

: None

Sends an upstream resume signal for 10 ms. This command is normally issued when the device is in suspend. The RESUME command is not

followed by a data read or write.

The PDIUSBH11 automatically sends a RESUME command when an event occurs downstream.

Read Current Frame Number

Command

: F5h

Data

: Read 1 or 2 bytes

This command is followed by one or two data reads and returns the frame number of the last successfully received SOF. The frame number is

returned Least Significant Byte first.

X

7

X

6

X

5

X

4

X

3

X

2

X

1

X

0

LEAST SIGNIFICANT BYTE

X

7

X

6

X

5

X

4

X

3

X

2

X

1

X

0

MOST SIGNIFICANT BYTE

SV00512

EMBEDDED FUNCTION

The USB host sees no difference between the embedded function and a function connected to one of the downstream ports. Some of the port

commands sent by the host must be handled appropriately by the embedded function to appear as any other downstream port.

The micro controller maintains a series of status and status change bits for the embedded function as described in the Get Port Status

command section. From these bits, the Status Change bit for the embedded function is derived (i.e. the port specific Status Change bits). This

Status Change bit is then provided to the PDIUSBH11 by the Set Status Change Bits command.