Philips Semiconductors

Product specification

PDIUSBH11

Universal Serial Bus Hub

1997 Aug 01

9

Data Flow Commands

Data flow commands are used to manage the data transmission between the USB endpoints and the monitor. Much of the data flow is initiated

via an interrupt to the microcontroller. The microcontroller utilizes these commands to access and determine whether the endpoint FIFOs have

valid data.

Read Interrupt Register

Command

: F4h

Data

: Read 1 byte

This command indicates the origin of an interrupt. A “1” indicates an interrupt occurred at this endpoint. The bits are cleared by reading the

endpoint status register through Read Endpoint Status command.

After a bus reset an interrupt will be generated, however all bits in the interrupt register will be 0. The interrupt is internally cleared by reading

the interrupt register. A bus reset is completely identical to the hardware reset through the RESET_N pin with the sole difference of interrupt

notification.

The hub interrupt endpoint is handled internally by the PDIUSBH11 hardware without the need of microcontroller intervention.

X

7

X

6

X

5

0

4

0

3

0

2

0

1

0

0

POWER ON VALUE

HUB CONTROL OUT ENDPOINT

HUB CONTROL IN ENDPOINT

FUNCTION CONTROL OUT ENDPOINT

FUNCTION CONTROL IN ENDPOINT

FUNCTION INTERRUPT ENDPOINT

RESERVED

SV00505

Select Endpoint

Command

: 00–04h

Data

: Optional Read 1 byte

The Select Endpoint command initializes an internal pointer to the start of the Selected buffer. Optionally, this command can be followed by a

data read, which returns 0 if the buffer is empty and 1 if the buffer is full.

X

7

X

6

X

5

X

4

X

3

X

2

X

1

0

0

POWER ON VALUE

FULL / EMPTY

RESERVED

FULL / EMPTY

A ‘1’ INDICATES THE BUFFER IS FULL, ‘0’ INDICATES AN EMPTY BUFFER

SV00506