Concurrent code checker and hardware efficient high-speed I/O having built-in self-test and debug features

• US 7,984,369 B2
• Filed: 01/19/2007
• Issued: 07/19/2011
• Est. Priority Date: 01/20/2006
• Status: Active Grant

• Current Assignee: Lattice Semiconductor Corporation
• Original Assignee: Silicon Image, Inc. (Lattice Semiconductor Corporation)
• Inventors: Ahn, Gijung, Choi, Hoon, Sul, Chinsong
• Primary Examiner(s): Torres; Joseph D
• Application Number:
  US11/656,331
• Publication Number:
  US 20070204204A1
• Time in Patent Office: 1,642 Days
• Field of Search: 714/809, 714/811
• US Class Current: 714/809
• CPC Class Codes: H03M 13/09 Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
• CPC Class Codes: H03M 13/6325 Error control coding in combination with demodulation
• CPC Class Codes: H03M 5/145 Conversion to or from block codes or representations thereof

Abstract

Method, device, and system for testing for errors in high-speed input/output systems. System and device may include a concurrent code checker for checking for errors in encoded data packets through data packets static properties and dynamic properties of the data stream including the packets. Method may involve detecting invalid encoded packets using the data packets static properties and the dynamic properties of the data stream including the packets. Method for optimizing a design of a concurrent code checker logic using don'"'"'t-care conditions, and concurrent code checker circuit having reduce logic element and semiconductor area requirements.

Claims

1. A high-speed input/output (HSIO) receiver comprising:

a deserializer configured for deserializing incoming serialized encoded data into an encoded data packet;

a code book configured to determine whether the encoded data packet is invalid, the code book including all valid code words of an encoding scheme and at least some invalid code words of the encoding scheme so long as the invalid code words satisfy at least one integrated circuit (IC) production test specification for performing a built-in self-test of an integrated circuit under test;

specification logic configured to check if the encoded data packet is valid or invalid, an invalid data packet violating the specifications of the code book; and

data packet error logic for registering a transmission error, in operation, if the encoded data packet is invalid.

2. The high-speed input/output (HSIO) receiver as in claim 1, wherein the receiver further comprises:

a concurrent code checker, and wherein the code book and the at least one integrated circuit (IC) production test specification are configured within the concurrent code checker.

3. The high-speed input/output (HSIO) receiver as in claim 2, wherein the at least one integrated circuit (IC) production test specification includes a DC integrated circuit (IC) production test specification and an RD integrated circuit (IC) production test specification.

4. The high-speed input/output (HSIO) receiver as in claim 3, wherein both the encoded data packets are checked individually for validity or invalidity and the data stream including multiple data packets is checked for validity or invalidity while still encoded using logical equations in the code book and the at least one integrated circuit (IC) production test specification including using a DC-balanced encoding scheme that DC-balances a data stream of code words and using a running disparity (RD) tracking of code words that tracks if a surplus of 0'"'"'s or 1'"'"'s have been received.

5. The high-speed input/output (HSIO) receiver as in claim 2, wherein the at least one test specification includes both a DC integrated circuit (IC) production test specification and an RD integrated circuit (IC) production test specification, and the DC and RD integrated circuit (IC) production test specifications are implemented as a finite-state-machine (FSM).

6. The high-speed input/output (HSIO) receiver as in claim 5, wherein the check for validity or invalidity is performed while the encoded data packets are still encoded using logical equations in the code book and the DC integrated circuit (IC) production test and the RD integrated circuit (IC) production test specifications.

7. The high-speed input/output (HSIO) receiver as in claim 2, wherein the code book is implemented to include at least one of a combinational logic circuit and a read-only memory (ROM).

8. The high-speed input/output (HSIO) receiver as in claim 2, wherein the at least one test specification is implemented using a finite-state-machine (FSM).

9. The high-speed input/output (HSIO) receiver as in claim 2, wherein the at least one test specification includes at least one of:

(i) a DC specification, and the receiver further comprising a DC logic unit which verifies the DC specification of a codeword and the DC specification of a data stream; and

(ii) an RD specification, and the receiver further comprising a RD logic unit which verifies the RD specification of a codeword and the RD specification of a data stream.

10. The high-speed input/output (HSIO) receiver as in claim 9, further comprising a bit-error-rate counter, wherein the bit-error-rate counter is incremented if the data packet is invalid.

11. The high-speed input/output (HSIO) receiver as in claim 9, further comprising:

a multiple input signature register (MISR), wherein, in operation, the MISR registers an error if the data packet is invalid.

12. The high-speed input/output (HSIO) receiver as in claim 2, further comprising a test clock control structure for halting a clock in order to examine internal registers if the data packet is invalid.

13. The high-speed input/output (HSIO) receiver as in claim 2, wherein the concurrent code checker includes a finite-state-machine (FSM) with four states, wherein, in operation, the FSM tracks a data stream of which the data packet is part.

14. The high-speed input/output (HSIO) receiver as in claim 13, wherein the FSM self synchronizes by extracting a starting point from the data stream.

15. The high-speed input/output (HSIO) receiver as in claim 13, further comprising a test clock control structure for halting a clock in order to examine internal registers if the data packet is invalid.

16. The high-speed input/output (HSIO) receiver as in claim 13, wherein, in operation, the FSM is configured to recover from errors so that continuous measurement of bit-error-rate (BER) can be carried out without interruption.

17. The high-speed input/output (HSIO) receiver as in claim 2, wherein, in operation, the MISR is independent of an employed encoding scheme.

18. The high-speed input/output (HSIO) receiver as in claim 2, wherein the concurrent code checker includes a plurality of finite-state-machines (FSM), wherein, in operation, a first FSM tracks the DC balance of a data stream including the encoded data packet and a second FSM tracks the running disparity (RD) value of the data stream.

19. The high-speed input/output (HSIO) receiver as in claim 2, wherein the code book is implemented using read-only memory, wherein, in operation, allowing configurable testing by allowing customizable RD values to encoded data packets.

20. The high-speed input/output (HSIO) receiver as in claim 2, wherein:

the concurrent code checker further includes;

a concurrent code checker logic configured to determine the DC value of a encoded data packet in a data stream; and

a finite state machine (FSM) configured to track the state of the data stream;

wherein, in operation, the concurrent code checker logic sends the DC value of the encoded data packet to the FSM which uses the DC value to determine if an error has occurred given the current state of the data stream.

21. The high-speed input/output (HSIO) receiver as in claim 2, wherein the deserializer, the concurrent code checker, and the decoder of the receiver are implemented on the same chip as a device to test to provide a built-in test capability for a device under test.

22. The high-speed input/output (HSIO) receiver as in claim 2, further comprising data packet error logic for registering a transmission error, in operation, if the encoded data packet is invalid.

23. The high-speed input/output (HSIO) receiver in claim 2, wherein the receiver further comprises a finite state machine (FSM);

the code checker determines a DC value of an encoded data packet in a data stream;

and the finite state machine (FSM) is configured to track the state of the data stream; and

the code checker includes means for sending the DC value of the encoded data packet to the FSM which uses the DC value to determine if an error has occurred given the current state of the data stream.

24. The high-speed input/output (HSIO) receiver in claim 2, wherein the code checker is implemented independent of a PRBS polynomial that can generate only a single pseudo-random pattern sequence, and wherein the code checker can check many pseudo-random pattern sequence.

25. The high-speed input/output (HSIO) receiver in claim 2, wherein the code checker is configured to operate in an online system mode, in an offline integrated circuit (IC) production test mode, and in a debugging mode, in response to control signals.

26. The high-speed input/output (HSIO) receiver in claim 2, wherein the code book is implemented by synthesizing the valid code words into logical equations which are applied to encoded data packets to check the data packet for invalidity.

27. The high-speed input/output (HSIO) receiver in claim 2, further including a test clock control structure (TCCS) used for halting a control clock and allowing debugging to occur and coupled to the code checker;

the TCCS operable for halting the control clock regulating a data bus on the receiver circuitry and for regulating the transmission of the data stream and allowing debugging to occur; and

the code checker being configured to halt operation of the receiver when an error occurs to allowing error debugging to proceed by examining internal values of registers.

28. The high-speed input/output (HSIO) receiver in claim 2, wherein the receiver includes multiple code checkers and is configured to receive and observe outputs of the multiple code checkers simultaneously and to capture a large number of errors should they occur without overflow.

29. The high-speed input/output (HSIO) receiver in claim 28, wherein the code delimiter detector is configured to use a special control character and the valid signal from code checker to synchronize a valid codeword boundary;

and

the RD FSM is enabled when a codeword boundary is detected, and checks for correct sequence of DC/RD.

30. The high-speed input/output (HSIO) receiver in claim 29, wherein the RD FSM is a self-synchronizing FSM.

31. The high-speed input/output (HSIO) receiver in claim 2, wherein the code checker further includes:

a code delimiter detector;

a code checker logic;

a running disparity finite state machine (RD FSM);

a MISR counter;

a clock halting circuit; and

the code checker produces a DC and/or RD value for a codeword passed to the DC/RD FSM.

32. The high-speed input/output (HSIO) receiver as in claim 2, wherein the receiver including the concurrent code checker is configured to operate without a Pseudo-Random Binary Sequence (PRBS) generator and test patterns are not limited to test patterns that can be generated by a Linear-Feedback Shift Register (LFSR) polynomial.

33. A high-speed input/output (HSIO) receiver comprising:

means for deserializing incoming serialized encoded data into an encoded data packet;

code book means for determining whether the encoded data packet is invalid, the code book means including all valid code words of an encoding scheme and at least some invalid code words of the encoding scheme so long as the invalid code words satisfy at least one integrated circuit (IC) production test specification for performing a built-in self-test of an integrated circuit under test;

specification logic means for checking if the encoded data packet is valid or invalid, an invalid data packet violating the specifications of the code book; and

registration means for registering a data packet transmission error, in operation, if the encoded data packet is invalid.

34. A method for operating a high-speed input/output (HSIO) receiver comprising:

deserializing incoming serialized encoded data into an encoded data packet;

determining using a code book whether the encoded data packet is invalid, the code book means including all valid code words of an encoding scheme and at least some invalid code words of the encoding scheme so long as the invalid code words satisfy at least one integrated circuit (IC) production test specification for performing a built-in self-test of an integrated circuit under test;

checking if the encoded data packet is valid or invalid, an invalid data packet violating an integrated circuit (IC) production logic test specification of the code book; and

registering a data packet transmission error, in operation, if the encoded data packet is invalid.

35. The method as in claim 34, wherein the method further comprises:

operating a concurrent code checker using the code book and the at least one integrated circuit (IC) production test specification within the concurrent code checker.

36. The method in claim 35, wherein, in operation, the specification logic checks the data packet for invalidity using static properties of the data packet and dynamic properties of a stream of data including the data packet.

37. The method in claim 35, wherein the data packet is a 10-bit codeword encoded using a DC-balanced clock-embedded encoding scheme.

38. The method in claim 35, wherein the code book comprises a plurality of values adapted for use in determining whether the 10-bit codeword is compliant with the encoding scheme used in encoding the data packet.

39. The method in claim 35, wherein the specification logic comprises eleven logical equations adapted for use in determining whether the 10-bit codeword is invalid.

40. The method in claim 35, wherein the incoming data is a stream of 10-bit code words and wherein, in operation, the specification logic determines whether the number of 1'"'"'s and 0'"'"'s is balanced in the stream of 10-bit code words.

41. The method in claim 35, wherein the incoming data is a stream of 10-bit code words and wherein, in operation, the specification logic determines whether the running disparity (RD) of the stream of 10-bit code words violates the encoding scheme.

42. The method in claim 41, wherein the specification logic comprises eleven logical equations configured for use in determining whether the 10-bit codeword is invalid.

43. The method in claim 35, further comprising incrementing a bit-error-rate counter if the data packet is invalid.

44. The method in claim 35, further comprising registering an error in a multiple input signature register (MISR) if the data packet is invalid.

45. The method in claim 35, further comprising halting a clock in order to examine internal registers if the data packet is invalid.

46. A The method in claim 35, wherein the specification logic includes a finite-state-machine (FSM) with four states, wherein, in operation, the FSM tracks a data stream which the data packet is part.

47. The method in claim 46, further comprising self-synchronizing the FSM by extracting the starting point from the data stream.

48. A The method in claim 46, wherein, in operation, the FSM recovering from errors so that continuous measurement of bit-error-rate (BER) can be carried out without interruption.

49. The method in claim 35, further comprising self synchronizing a multiple input signature register (MISR).

50. The method in claim 49, wherein, in operation, the MISR is independent of employed encoding scheme.

51. The method in claim 35, wherein the specification logic includes a plurality of finite-state-machines (FSM), wherein, in operation, (i) tracking with a first FSM, the DC balance of a data stream including the encoded data packet;

and (ii) tracking with a second FSM the running disparity (RD) value of the data stream.

52. The method in claim 35, further comprising:

implementing the code book using read-only memory, wherein, in operation, allowing configurable testing by allowing customizable RD values to encoded data packets.

53. The method in claim 35, wherein:

the checking, using specification logic, includes,

detecting errors with an error detection circuitry including;

determining, using a concurrent code checker (C3) logic, the DC value of a encoded data packet in a data stream; and

tracking, in a finite state machine (FSM), the state of the data stream;

wherein, in operation, the C3 logic sending the DC value of the encoded data packet to the FSM which uses the DC value for determining if an error has occurred given the current state of the data stream.

54. The method in claim 35, further comprising:

programming at least one register in the concurrent code checker (C3) logic to configure the system into a testing mode;

monitoring code words and determining a number of valid code words detected;

if a predetermined number of valid code words are detected, a test control circuitry in a code delimiter detector (CDD) enabling a running disparity finite state machine (RD FSM) to check validity of a data stream;

when the RD FSM is enabled, using the RE FSM to monitor the data stream and to properly synchronize to the data stream;

after synchronization, the C3 continuously tracking the test specification until done; and

when testing is completed, disabling the C3 logic.

55. The method as in claim 54, wherein the configuring of the system into a testing mode comprises configuring the system into an online testing mode, and the online testing mode further comprises:

enabling a valid codeword (valCW) in the code delimiter detector (CDD) to synchronize beginning of a data stream; and

configuring code error checker control signal (CEC_en) for enabling a CEC and a DC/RD control signals (DC or RD spec check) for selecting a test specification from available test specifications.

56. A non-transient computer readable media comprising a computer program stored therein including instructions for controlling the operation of a high-speed input/output (HSIO) receiver including a computing device having a processing logic, the instructions including instructions for performing the steps of a method for receiving comprising:

deserializing incoming serialized encoded data into an encoded data packet;

determining using a code book whether the encoded data packet is invalid, the code book means including all valid code words of an encoding scheme and at least some invalid code words of the encoding scheme so long as the invalid code words satisfy at least one integrated circuit (IC) production test specification for performing a built-in self-test of an integrated circuit under test;

checking if the encoded data packet is valid or invalid, an invalid data packet violating an integrated circuit (IC) production logic test specification of the code book; and

registering a data packet transmission error, in operation, if the encoded data packet is invalid.