PDIUSBH11NB PHILIPS [NXP Semiconductors], PDIUSBH11NB Datasheet - Page 12

• Manufacturer Part Number: PDIUSBH11NB
• Description: Universal Serial Bus Hub
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
Clear Buffer
Command
Data
When a packet is received completely, an internal endpoint buffer full flag is set. All subsequent packets will be refused by returning a NACK.
When the microcontroller has read the data, it should free the buffer by the Clear Buffer command. When the buffer is cleared new packets will
be accepted.
Validate Buffer
Command
Data
When the microprocessor has written data into an IN buffer, it should set the buffer full flag by the Validate Buffer command. This indicates that
the data in the buffer are valid and can be sent to the host when the next IN token is received.
Set Endpoint Status
Command
Data
A stalled control endpoint is automatically unstalled when it receives a SETUP token, regardless of the content of the packet. If the endpoint
should stay in its stalled state, the microcontroller can re–stall it.
When a stalled endpoint is unstalled (either by the Set Endpoint Status command or by receiving a SETUP token), it is also re–initialized. This
flushes the buffer and if it is an OUT buffer it waits for a DATA 0 PID, if it is an IN buffer it writes a DATA 0 PID.
Even when unstalled, writing Set Endpoint Status to ‘0’ initializes the endpoint.
Acknowledge Setup
Command
Data
The arrival of a SETUP packet flushes the IN buffer and disables the Validate Buffer and Clear Buffer commands for both IN and OUT
endpoints.
The microcontroller needs to re–enable these commands by the Acknowledge Setup command. This ensures that the last SETUP packet stays
in the buffer and no packet can be sent back to the host until the microcontroller has acknowledged explicitly that it has seen the SETUP packet.
The microcontroller must send the Acknowledge Setup command to both the IN and OUT endpoints.
1997 Aug 01
Universal Serial Bus Hub
STALLED
7
X
6
X
5
X
: F2h
: None
: FAh
: None
: 40–44h
: Write 1 byte
: F1h
: None
A ‘1’ INDICATES THE ENDPOINT IS STALLED
4
X
3
X
2
X
1
X
0
0
POWER ON VALUE
STALLED
RESERVED
SV00509
12
PDIUSBH11
Product specification