PDIUSBD12
USB interface device with parallel bus
Philips Semiconductors
This command is useful for debugging purposes. Since it keeps track of every
transaction, the status information is overwritten for each new transaction.
See Table 9 for bit allocation.
Fig 13. Read last transaction status register.
Table 9:
Read last transaction status register: bit allocation
Bit
Symbol
Description
7
PREVIOUS STATUS
NOT READ
A ‘1’ indicates a second event occurred before the
previous status was read.
6
5
DATA 0/1 PACKET
A ‘1’ indicates the last successful received or sent packet
had a DATA1 PID.
SETUP PACKET
A ‘1’ indicates the last successful received packet had a
SETUP token (this will always read ‘0’ for IN buffers).
4 to 1 ERROR CODE
See Table 10 “Error codes”.
0
DATA
A ‘1’ indicates data has been received or transmitted
successfully.
RECEIVE/TRANSMIT
SUCCESS
Table 10: Error codes
Error
Description
code (Binary)
0000
0001
0010
0011
No Error
PID encoding Error; bits 7 to 4 are not the inversion of bits 3 to 0
PID unknown; encoding is valid, but PID does not exist
Unexpected packet; packet is not of the type expected (= token, data or
acknowledge), or SETUP token to a non-control endpoint
0100
0101
0110
0111
1000
1001
1010
Token CRC Error
Data CRC Error
Time Out Error
Never happens
Unexpected End-Of-Packet
Sent or received NAK
Sent Stall, a token was received, but the endpoint was stalled
9397 750 09238
© Koninklijke Philips Electronics N.V. 2001. All rights reserved.
Product data
Rev. 08 — 20 December 2001
18 of 35
NXP [ NXP ]
