Philips Semiconductors

Product specification

PDIUSBD11

USB device with serial interface

1999 Jul 22

9

Read Last Transaction Status

Command

: 40–4Dh

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.

POWER ON VALUE

DATA RECEIVE/TRANSMIT SUCCESS

ERROR CODE (SEE TABLE)

SETUP PACKET

DATA 0/1 PACKET

PREVIOUS STATUS NOT READ

76

5

4

3

2

0

1

0

0

00

00

00

SV00832

Data Receive/

Transmit Success

A ‘1’ indicates data has been received

or transmitted successfully.

Error Code

See Table 1, Error Codes.

Setup Packet

A ‘1’ indicates the last successful

received packet had a SETUP token

(this will always read ‘0’ for IN buffers).

Data 0/1 Packet

A ‘1’ indicates the last successful

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.

Table 1.

ERROR CODES

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

Read Endpoint Status

Command

: 80–8Dh

Data

: Read 1 byte

POWER ON VALUE

RESERVED

SETUP PACKET

STALL

DATA 0/1 PACKET

BUFFER FULL

76

5

4

3

2

X

1

X

0

00

00

XX

SV00833

RESERVED

Setup Packet

A ‘1’ indicates the last received packet had a

SETUP token.

STALL

A ‘1’ indicates the endpoint is stalled.

Data 0/1 Packet

A ‘1’ indicates if the last received or sent packet

had a DATA1 PID.

Buffer Full

A ‘1’ indicates that the buffer is full.

Read Buffer

Command

: F0h

Data

: Read multiple bytes (max 10)

The Read Buffer command is followed by a number of data reads,

which return the contents of the selected endpoint data buffer. After

each read, the internal buffer pointer is incremented by 1.

The buffer pointer is not reset to the buffer start by the Read Buffer

command. This means that reading or writing a buffer can be

interrupted by any other command (except for Select Endpoint), or

to get the number of data bytes, then read the rest in other

transactions).

The data in the buffer are organized as follows:

. . . . . .

Write Buffer

Command

: F0h

Data

: Write multiple bytes (max 10)

The Write Buffer command is followed by a number of data writes,

which load the endpoints buffer. The data must be organized in the

same way as described in the Read Buffer command. The first byte

(reserved) should always be ‘0’. As in the Read Buffer command,

WARNING:

There is no protection against writing or reading over a buffer’s

boundary or against writing into an OUT buffer or reading from an IN

buffer. Any of these actions could cause an incorrect operation. Data

in an OUT buffer are only meaningful after a successful transaction.