Self-diagnostic circuit and self-diagnostic method for detecting errors

• US 7,904,771 B2
• Filed: 11/26/2008
• Issued: 03/08/2011
• Est. Priority Date: 11/27/2007
• Status: Expired due to Fees

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Mochizuki, Hideo
• Primary Examiner(s): Kerveros; James C
• Application Number:
  US12/292,862
• Publication Number:
  US 20090138767A1
• Time in Patent Office: 832 Days
• Field of Search: 714/704, 714/724
• US Class Current: 714/724
• CPC Class Codes: G01R 31/317 Testing of digital circuits
• CPC Class Codes: G01R 31/31704 Design for test; Design verification concerning scan tests G01R31/318583; computer-aided design G06F30/00

Abstract

A self-diagnostic circuit includes a setting unit receiving a plurality of detection signals generated in an integrated circuit device, and determining a type of detection signal to be detected among the received plurality of detection signals. A counter is coupled to the setting unit and counts a number of a signal corresponding to the type of the detection signal to be detected.

Claims

1. A self-diagnostic circuit, comprising:

a setting unit configured to receive a plurality of detection signals generated in an integrated circuit device, to output a first signal when the setting unit receives at least one of the detection signals, and to output a second signal when the setting unit receives a specific one of the detection signals, wherein the setting unit does not output the second signal when the setting unit receives detection signals other than the specific one of the detection signals; and

a counter coupled to the setting unit and configured to count a number of the first signal inputted into the counter;

wherein the self-diagnostic circuit determines whether the number of the first signal is within a first predetermined range, and the counter is configured to further count a number of the second signal inputted into the counter after counting the number of the first signal if the number of the first signal is within the first predetermined range, and

wherein the self-diagnostic circuit specifies an occurred error based on determining whether the number of the second signal is within a second predetermined range.

2. The self-diagnostic circuit according to claim 1, wherein the setting unit comprises:

a setting register holding a setting information, and generating a masking control signal indicating that which one of the detection signals is the specific one of the detection signals; and

a masking circuit receiving the detection signals, and masking the received detection signals in a response to the masking control signal.

3. The self-diagnostic circuit according to claim 2, wherein the masking circuit comprises an AND circuit.

4. The self-diagnostic circuit according to claim 2, wherein the setting unit further comprises:

a plurality of the masking circuit respectively receiving one of the detection signals; and

an OR circuit coupled to the plurality of the masking circuit, and generating the first signal or the second signal.

5. The self-diagnostic circuit according to claim 2, wherein the detection signal comprises an error detection signal.

6. The self-diagnostic circuit according to claim 5, wherein the self-diagnostic circuit determines a presence or an absence of a malfunction of the integrated circuit device based on a number of the second signal counted per unit time.

7. The self-diagnostic circuit according to claim 2, wherein the mask control signal indicates that a detection signal other than a detection signal showing an error in accessing a cache memory of the integrated circuit device is masked.

8. The self-diagnostic circuit according to claim 1, wherein the integrated circuit device comprises:

a main circuit operating based on a first clock;

an evaluation circuit operating based on a second clock having a frequency higher than that of the first clock; and

a deterioration detector outputting a deterioration detection signal indicative of deterioration of a circuit in response to an output of the evaluation circuit,

wherein the deterioration detection signal is inputted into the setting unit.

9. The self-diagnostic circuit according to claim 1, wherein the setting unit is configured to receive a command execution flag as one of the detection signals to output a third signal to the counter, and to receive a cache error flag as one of the detection signals to output a fourth signal to the counter,

wherein the counter is configured to count a number of the third signal inputted into the counter and to count a number of the fourth signal inputted into the counter, and

wherein the self-diagnostic circuit determines that a target program has an infinite loop based on a difference between the number of the third signal and the number of the fourth signal.

10. The self-diagnostic circuit according to claim 9, wherein a setting of the setting unit is changed in a response to an acquired number of signals which fall other than into the infinite loop.

11. The self-diagnostic circuit according to claim 1, wherein the setting unit is configure to receive a Direct Memory Access (DMA) access flag as one of the detection signals to output a fifth signal to the counter,

wherein the counter is configured to count a number of the fifth signal inputted into the counter, and

wherein the self-diagnostic circuit determines that the DMA is in a deadlock based on the number of the fifth signal.

12. The self-diagnostic circuit according to claim 1, wherein the setting unit is configured to receive a communication retry flag as one of the detection signals to output a sixth signal to the counter,

wherein the counter is configured to count a number of the sixth signal inputted into the counter, and

wherein the self-diagnostic circuit detects a malfunction of another integrated circuit which is a communication target is occurred based on the number of the sixth signal.

13. The self-diagnostic circuit according to claim 1, wherein the counter counts a number of said detection signals that correspond to a type of the detection signals.