Philips Semiconductors

Product specification

PDIUSBH11

Universal Serial Bus Hub

1997 Aug 01

10

Read Last Transaction Status

Command

: 40–44h

Data

: Read 1 byte

The

Read Last Transaction Status command is followed by one data read that returns the status of the last transaction of the endpoint. This

command also resets the corresponding interrupt flag in the interrupt register, and clears the status, indicating that it was read.

This command is useful for debugging purposes. Since it keeps track of every transaction, the status information is overwritten for each new

transaction.

0

7

0

6

0

5

0

4

0

3

0

2

0

1

0

0

POWER ON VALUE

DATA RECEIVE / TRANSMIT SUCCESS

ERROR CODE (SEE TABLE 1)

SETUP PACKET

DATA 0/1 PACKET

PREVIOUS STATUS NOT READ

DATA RECEIVE / TRANSMIT SUCCESS

A ‘1’ INDICATES DATA HAS BEEN RECEIVED OR TRANSMITTED SUCCESSFULLY

ERROR CODE

SEE TABLE 1

SETUP PACKET

A ‘1’ INDICATES THE LAST RECEIVED PACKET HAD A SETUP TOKEN (THIS ALWAYS READ ‘0’ FOR IN BUFFERS.

DATA 0/1 PACKET

A ‘1’ INDICATES THAT THE LAST RECEIVED OR SENT PACKET HAD A DATA1 PID

PREVIOUS STATUS NOT READ

A ‘1’ INDICATES A SECOND EVENT OCCURRED BEFORE THE PREVIOUS STATUS WAS READ.

SV00507

Table 1.

ERROR CODE

RESULT

0000

No Error

0001

PID Encoding Error, Bits 7–4 are not the inversion of bits 3–0

0010

PID Unknown, encoding is valid, but PID does not exist

0011

Unexpected Packet, Packet is not of the type expected (= token, data or acknowledge), or SETUP token to a

non-control endpoint

0100

Token CRC Error

0101

Data CRC Error

0110

Time Out Error

0111

Babble Error

1000

Unexpected End of Packet

1001

Sent or Received NAK

1010

Sent Stall, a token was received, but the endpoint was stalled

1011

Overflow Error, the received packet was longer than the available buffer space

1101

Bitstuff Error

1111

Wrong DATA PID, the received DATA PID was not the expected one