Systems and methods for implementing cyclic redundancy checks

• US 20060168496A1
• Filed: 11/23/2005
• Published: 07/27/2006
• Est. Priority Date: 11/24/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Steele, Brian, Wiley, George A.
• Granted Patent: US 8,667,363 B2
• Time in Patent Office: Days
• US Class Current: 714/758
• CPC Class Codes: H03M 13/09 Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0061 Error detection codes

Abstract

The present invention provides systems and methods for implementing cyclic redundancy checks to improve link initialization processing and to exchange system error information. In one aspect, a cyclic redundancy check (CRC) checker is provided that includes a unique pattern detector, a CRC generator, a CRC initializer and a CRC verifier. The CRC checker prepopulates the CRC generator for a unique pattern. Upon receipt of the unique pattern within a data stream received over a digital transmission link, the CRC checker proceeds to check CRCs without the need to queue and store data. In another aspect, a CRC generator system is provided that intentionally corrupts CRC values to transmit system error information. The CRC generator system includes a CRC generator, a CRC corrupter, an error detector and an error value generator. In one example, the digital transmission link is an MDDI link.

Claims

1. A cyclic redundancy check (CRC) checker comprising:

a unique pattern detector that detects a unique pattern within a data stream received over a digital transmission link;

a CRC generator that generates CRC values based on the received data stream;

a CRC initializer; and

a CRC verifier that detects differences between a CRC value generated based on a received data stream to a CRC value that was sent within the received data stream.

2. The CRC checker of claim 1, wherein the CRC initializer prepopulates the CRC generator with the unique pattern upon link initialization

3. The CRC checker of claim 1, wherein the CRC initializer prepopulates the CRC verifier with a CRC value associated with the unique pattern.

4. The CRC checker of claim 1, that The CRC checker of claim 1, wherein the digital transmission link is an MDDI transmission link.

5. The CRC checker of claim 1, wherein the unique data pattern includes the packet length, packet type and unique word fields within a sub-frame header packet.

7. The method of claim 5, wherein said digital transmission link is an MDDI transmission link.

6. A method for initializing a digital transmission link, comprising:

(a) receiving a request to initialize the digital transmission link;

(b) pre-populating a CRC generator with a CRC value corresponding to a unique data pattern;

(c) disabling the CRC generator;

(d) monitoring an incoming data stream to detect the unique data pattern; and

(e) upon detecting the unique data pattern, enabling the CRC generator.

8. The method of claim 6, wherein the unique data pattern includes the packet length, packet type and unique word fields of a sub-frame header packet.

10. The CRC generator system of claim 8, further comprising an error value generator that instructs the CRC corrupter to replace a CRC value generated by the CRC generator with a CRC error value that indicates a type of system error or status condition.

11. The CRC generator system of claim 8, wherein said digital transmission link is an MDDI transmission link.

13. The CRC checker of claim 11, wherein the digital transmission link is an MDDI transmission link.

15. The method of claim 13, further comprising transmitting the corrupted CRC value within a data packet over the digital transmission link.

16. The method of claim 13, wherein said digital transmission link is an MDDI link.

18. The method of claim 16, wherein the CRC error value is transmitted within a data packet over the digital transmission link.

19. The method of claim 16, wherein the digital transmission link is a MDDI link.

9. A cycle redundancy check (CRC) generator system within a host system, comprising:

a CRC generator that generates a CRC value based on data to be included in a data packet to be transmitted over a digital transmission link;

a CRC corrupter that corrupts a CRC value generated by the CRC generator to convey host or related system status information;

an error detector that detects an error condition within a host system and provides instructions for the CRC corrupter to intentionally corrupt a CRC value.

12. A cycle redundancy check (CRC) checker, comprising:

a CRC error value detector that detects CRC error values within a CRC field of a data packet received over a digital transmission link, wherein the CRC error values identify system or related system error conditions;

a cyclic redundancy check (CRC) generator that generates CRC values based on a received data stream;

a CRC verifier that detects differences between a CRC value generated based on a received data stream to a CRC value that was sent within the received data stream.

14. A method to transmit system error information from a host system over a digital transmission link, comprising:

(a) detecting a host system or related system error;

(b) generating a CRC value based on data to be transmitted within a packet over the digital transmission link; and

(c) corrupting the CRC value, wherein the corruption indicates that the host system or related system error has occurred.

17. A method to transmit system error information from a host system over a digital transmission link, comprising:

(a) detecting a host system or related system error;

(b) generating a CRC value based on data to be transmitted within a packet over the digital transmission link;

(c) determining a CRC error value based on the type of error detected in step (a); and

(d) replacing the CRC value generated in step (b) with the CRC error value generated in step (c), wherein the CRC error value indicates a specific type of error condition within the host or related system.