Methods for embedding an out-of-band signal into a USB capture stream

• US 8,990,447 B1
• Filed: 03/31/2009
• Issued: 03/24/2015
• Est. Priority Date: 03/31/2008
• Status: Active Grant

• Current Assignee: Total Phase, Inc.
• Original Assignee: Total Phase, Inc.
• Inventors: Santhanam, Kumaran, Santhanam, Gopal, Bruhis, Etai
• Primary Examiner(s): Abad, Farley
• Assistant Examiner(s): YU, HENRY W
• Application Number:
  US12/416,102
• Time in Patent Office: 2,184 Days
• Field of Search: 710 15- 19, 710 52- 57, 710/105, 710/109, 710/306, 710/311, 714/39, 714/724, 341/68, 370/438
• US Class Current: 710/16
• CPC Class Codes: G06F 13/4282 on a serial bus, e.g. I2C bus, SPI bus on daisy chain buses G06F13/4247
• CPC Class Codes: G06F 2213/0042 Universal serial bus [USB]
• CPC Class Codes: G06F 3/00 Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
• CPC Class Codes: G08C 25/00 Arrangements for preventing or correcting errors; Monitoring arrangements
• CPC Class Codes: H03M 13/00 Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes error detection or error correction for analogue/digital, digital/analogue or code conversion H03M1/00 – H03M11/00; specially adapted for digital computers G06F11/08; for information storage based on relative movement between record carrier and transducer G11B, e.g. G11B20/18; for static stores G11C
• CPC Class Codes: H04L 12/40 Bus networks
• CPC Class Codes: H04L 12/40169 Flexible bus arrangements arrangements for maintenance or administration involving management of faults; events, alarms H04L41/06; automatic restoration of network faults H04L41/0654
• CPC Class Codes: H04L 43/04 Processing captured monitoring data, e.g. for logfile generation
• CPC Class Codes: H04L 43/18 Protocol analysers
• CPC Class Codes: H04L 65/75 Media network packet handling

Abstract

One or more out-of-band input signals (GPIO) are handled and efficiently embedded into a USB capture stream. In order to conserve resources, the state of the input signals can be sent only when a change occurs. The signals are accurately time-stamped, and then presented within the context of the captured USB data. In order to provide maximum visibility, if the digital inputs occur during a normally filtered multi-packet sequence, the filter is canceled and the surrounding packets will also be sent to an analysis computer. Furthermore, because digital inputs may happen during a USB packet, the digital inputs are queued in a FIFO buffer until there is an opportunity to send the digital inputs. Even though the state of the inputs may be sent at a later time, the state of the inputs may be time-stamped when the state of the inputs is perceived by the analyzer.

Claims

1. A method for monitoring a USB data stream between a source and a destination, wherein said USB data stream comprises of a plurality of USB packets, comprising the steps of:

receiving a stream of one or more USB packets from a USB input line;

receiving non-USB-related signals from a general purpose input line;

processing with a processor the stream of one or more USB packets and the non-USB-related signals;

interleaving change of state information of the non-USB-related signals with the stream of one or more processed USB packets as an analysis stream without interleaving the non-USB-related signals with the stream, wherein the change of state information includes a change of state in the non-USB-related signals and a timestamp corresponding to the change of state, and wherein the change of state information of the non-USB-related signals is different from the non-USB-related signals; and

sending the analysis stream to an analysis computer.

2. The method of claim 1 wherein at least some of the non-USB-related signals causes filtering of the USB packets.

3. The method of claim 2 wherein the filtering is for the filtering of a defined type of packets.

4. The method of claim 1 wherein at least some of the non-USB-related signals ceases the filtering of the USB packets.

5. The method of claim 4 wherein the filtering is ceased for a pre-defined period of time.

6. The method of claim 4 wherein the filtering is ceased for a pre-defined number of packets.

7. The method of claim 1, wherein receiving the stream of one or more USB packets comprises storing the USB packets in a packet buffer of the analyzer.

8. The method of claim 7 wherein the USB packets are processed in the packet buffer as a function of the non-USB-related signals.

9. The method of claim 1, wherein the interleaving is based at least in part on a timing of the information.

24. The method of claim 1, wherein the information is interleaved in an order reflecting timing of the change of state with respect to the stream of one or more USB packets.

10. A method for managing a data capture stream for a USB host and a device using an analyzer having a packet buffer, comprising the steps of:

receiving one or more USB packets from a USB input line into a packet buffer;

receiving non-USB-related signals from a general purpose input line;

if a change is detected with respect to at least some of the non-USB-related signals, recording that the change has been detected and recording a timestamp corresponding to the change;

inserting the change and the timestamp of the non-USB-related signals in the packet buffer such that the change and the timestamp are interleaved with the one or more USB packets in the packet buffer; and

generating a data capture stream from the packet buffer.

11. The method of claim 10 wherein if a change in the non-USB-related signal is received during the reception of a USB packet, recording comprises storing the change and the timestamp in an input buffer and inserting the change and the timestamp in the packet buffer after the completion in the reception of the USB packet.

12. The method of claim 11 wherein the timestamp indicates the time when the change in the non-USB-related signals was initially detected.

13. The method of claim 10 wherein the one or more USB packets are part of a filtered multi-packet sequence.

14. The method in claim 13 wherein if the change in the non-USB-related signal is received during the reception of the filtered multi-packet sequence, recording comprises storing the change and the timestamp in an input buffer and inserting the change and the timestamp in the packet buffer after the completion of a packet in the reception of the multi-packet sequence.

15. A system for monitoring a USB data stream between a source and a destination, comprising:

an interface configured to

receive a stream of one or more USB packets from a USB input line; and

receive non-USB-related signals from a general purpose input line; and

a processor coupled to the interface, configured to;

process the stream of one or more USB packets and the non-USB-related signals;

interleave change of state information of the non-USB-related signals with the stream of one or more processed USB packets as an analysis stream without interleaving the non-USB-related signals with the stream, wherein the change of state information includes a change of state in the non-USB-related signals and a timestamp corresponding to the change of state, and wherein the change of state information of the non-USB-related signals is different from the non-USB-related signals; and

send the analysis stream to an analysis computer.

16. The system of claim 15, wherein at least some of the non-USB-related signals causes filtering of the USB packets.

17. The system of claim 16, wherein the filtering is for the filtering of a defined type of packets.

18. The system of claim 15, wherein at least some of the non-USB-related signals ceases the filtering of the USB packets.

19. The system of claim 18, wherein the filtering is ceased for a pre-defined period of time.

20. The system of claim 18, wherein the filtering is ceased for a pre-defined number of packets.

21. The system of claim 15, wherein receiving the stream of one or more USB packets comprises storing the USB packets in a packet buffer of the analyzer.

22. The system of claim 21, wherein the USB packets are processed in the packet buffer as a function of the non-USB-related signals.

23. The system of claim 15, wherein the interleaving is based at least in part on a timing of the information.

25. The system of claim 15, wherein the information is interleaved in an order reflecting timing of the change of state with respect to the stream of one or more USB packets.