Method and apparatus for verifying the integrity of control module operation

• US 6,952,795 B2
• Filed: 10/24/2001
• Issued: 10/04/2005
• Est. Priority Date: 09/24/2001
• Status: Expired due to Fees

• Current Assignee: Temic Automotive of North America, Incorporated (Continental AG)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Ferrell, Shawn, O'Gorman, Patrick A., Grai, Tim
• Primary Examiner(s): Iqbal, Nadeem
• Assistant Examiner(s): Bonura, Timothy M.
• Application Number:
  US10/000,609
• Publication Number:
  US 20030061548A1
• Time in Patent Office: 1,441 Days
• Field of Search: 714/33, 714/37, 714/43, 714/47
• US Class Current: 714/33
• CPC Class Codes: G06F 11/08 Error detection or correction by redundancy in data representation, e.g. by using checking codes
• CPC Class Codes: G06F 11/221 to test buses, lines or interfaces, e.g. stuck-at or open line faults

Abstract

A control module (100) includes a first signal processing unit (102) that is coupled to a second signal processing unit (114) by a control bus (130), an address bus (131) and a data bus (132). The control module conveys seed value addresses (108) and expected result addresses (110) over the address bus, seed values (118) and verification set output values (107) over the data bus, and compares each verification set output value to an expected result (120), thereby allowing the control module to determine whether the first signal processing unit, the control bus, the address bus, and the data bus are collectively functioning correctly. By properly selecting the seed value addresses, expected result addresses, seed values, and expected results (and correspondingly, verification set output values), proper operation of each line of the address bus and control bus may be individually verified.

Claims

1. A method for verifying the integrity of operation of a control module having a digital signal processing unit, the method comprising steps of:

conveying a seed value to the digital signal processing unit;

incrementing a stored state value;

executing, by the digital signal processing unit, a set of verification instructions based on the seed value to produce a verification set output value;

receiving, from the digital signal processing unit, the verification set output value;

further incrementing the stored state value to produce a twice incremented second state value;

comparing the verification set output value to an expected result to produce a comparison; and

determining whether an error has occurred based on the comparison.

2. The method of claim 1, further comprising steps of:

receiving, from the digital signal processing unit and via an address bus, a seed value address corresponding to a storage location of the seed value; and

determining the seed value based on the received seed value address.

3. The method of claim 1, further comprising a step of receiving, from the digital signal processing unit and via an address bus, a expected result address corresponding to a storage location of the expected result, and wherein the step of determining whether an error has occurred comprises a step of determining whether an error has occurred based on the comparison and on the received expected result address.

4. The method of claim 3, further comprising a step of retrieving the expected result based upon the received expected result address.

5. The method of claim 1, further comprising a step of retrieving the expected result based upon a stored state value.

6. The method of claim 1, further comprising a step of determining that an error has occurred when a predetermined amount of time expires after conveying the seed value to the digital signal processing unit and prior to receiving the verification set output value from the digital signal processing unit.

7. The method of claim 1, wherein the stored state value comprises a first state value, wherein the digital signal processing unit stores a second state value, and wherein the method further comprising steps of:

incrementing, by the digital signal processing unit, the second state value upon receiving the seed value;

conveying, by the digital signal processing unit, the verification set output value;

further incrementing, by the digital signal processing unit, the second state value upon conveying the verification set output value to produce a twice incremented second state value.

8. A method for verifying the integrity of operation of a control module having a first digital signal processing unit coupled to second digital signal processing unit, wherein the first digital signal processing unit stores a set of verification instructions, wherein the first digital signal processing unit stores a plurality of seed value addresses and the second digital signal processing unit stores a plurality of seed values and a plurality of expected results, the method comprising steps of:

(a) conveying, by the second digital signal processing unit to the first digital signal processing unit, a seed value of the plurality of seed values, wherein this step includes the substeps of;

conveying, by the first digital signal processing unit to the second digital signal processing unit, a seed value address of the plurality of seed value addresses,

receiving, by the second digital signal processing unit, the seed value address,

retrieving, by the second digital signal processing unit, a seed value, and

conveying, by the second digital signal processing unit, the retrieved seed value;

(b) executing, by the first digital signal processing unit, the set of verification instructions based on the seed value to produce a verification set output value;

(c) conveying, by the first digital signal processing unit to the second digital signal processing unit, the verification set output value;

(d) comparing, by the second digital signal processing unit, the verification set output value to a corresponding expected result of the plurality of expected results to produce a comparison;

(e) determining whether an error has occurred based on one or more of the comparison of the received verification set output value to a corresponding expected result and the received seed value address;

(f) determining whether a predetermined number of iterations of steps (b) through (e) have been completed; and

(g) when fewer than the predetermined number of iterations have been completed, conveying a succeeding seed value of the plurality of seed values to the first digital signal processing unit and repeating steps (b) through (f).

9. The method of claim 8, wherein the seed value is retrieved based on a state value stored in the second digital signal processing unit.

10. The method of claim 8, wherein the seed value is retrieved based on the received seed value address.

11. The method of claim 8, further comprising a step of:

(h) determining that an error has occurred when a predetermined amount of time expires after conveying the seed value to the first digital signal processing unit and prior to receiving the verification set output value from the first digital signal processing unit; and

wherein step (g) comprises a step of, when fewer than the predetermined number of iterations have been completed, conveying a succeeding seed value of the plurality of seed values to the digital signal processing unit and repeating steps (b) through (f) and (h).

12. The method of claim 8, wherein the processor further stores a plurality of expected result addresses, wherein each expected result address of the plurality of expected result addresses corresponds to an expected result of the plurality of expected results, and wherein the method further comprises a step of:

(h) conveying, by the first digital signal processing unit to the second digital signal processing unit, an expected result address of the plurality of expected result addresses; and

wherein step (e) comprises a step of determining an error based on one or more of the comparison of the received verification set output value to the corresponding expected result and the received expected result address, wherein step (f) comprises a step of determining whether a predetermined number of iterations of steps (b) through (e) and (h) have been completed, and wherein step (g) comprises steps of, when fewer than the predetermined number of iterations have been completed, conveying, by the second digital signal processing unit, a succeeding seed value of the plurality of seed values to the first digital signal processing unit, conveying, by the first digital signal processing unit, a succeeding expected result address of the plurality of secondary expected result addresses, and repeating steps (b) through (g) and (h).

13. The method of claim 12, wherein the first digital signal processing unit further stores a first state value, wherein the second digital signal processing unit farther stores a second state value, and wherein the method farther comprises steps of:

(i) incrementing, by the second digital signal processing unit, the second state value upon conveying the seed value to the digital signal processing unit; and

(j) farther incrementing, by the second digital signal processing unit, the second state value upon receiving the verification set output value to produce a twice incremented second state value;

(k) incrementing, by the first digital signal processing unit, the first state value upon receiving the seed value;

(l) further incrementing, by the first digital signal processing unit, the first state value upon conveying the verification set output value to produce a twice incremented first state value; and

wherein step (e) comprises a step of determining an error based on the comparison of the received verification set output value to the corresponding expected result and the received expected result address, wherein step (f) comprises a step of determining whether a predetermined number of iterations of steps (b) through (e) and (i) through (l) have been completed, and wherein step (g) comprises steps of, when fewer than the predetermined number of iterations have been completed, conveying, by the second digital signal processing unit, a succeeding seed value of the plurality of seed values to the first digital signal processing unit, conveying, by the first digital signal processing unit, a succeeding expected result address of the plurality of expected result addresses, and repeating steps (b) through (f) and (i) through (l).

14. A control module that self-verifies the integrity of the control module'"'"'s operations, the control module comprising:

a first digital signal processing unit that receives a seed value from a second digital signal processing unit, executes a set of verification instructions based on the seed value to produce a verification set output value, and conveys the verification set output value to the second digital signal processing unit; and

a second digital signal processing unit coupled to the first digital signal processing unit that stores the seed value and an expected result, retrieves the seed value based on a received seed value address received from the first digital signal processing unit, conveys the seed value to the first digital signal processing unit, receives the verification set output value from the first digital signal processing unit, compares the received verification set output value to the expected result to produce a comparison, and determines whether an error has occurred based on the comparison.

15. The control module of claim 14, further comprising a data bus coupling the first digital signal processing unit to the second digital signal processing unit, wherein the second digital signal processing unit conveys the seed value to the first digital signal processing unit via the data bus and the first digital signal processing unit conveys the verification set output value to the second digital signal processing unit via the data bus.

16. The control module of claim 14, further comprising an address bus coupling the first digital signal processing unit to the second digital signal processing unit, wherein the first digital signal processing unit further stores a seed value address corresponding to a location of the seed value in the second digital signal processing unit and conveys the seed value address to the second digital signal processing unit via the address bus, wherein the second digital signal processing unit conveys the seed value to the digital signal processing unit in response to receiving the seed value address, and wherein the second digital signal processing unit determines whether an error has occurred based on the received seed value address.

17. The control module of claim 14, further comprising an address bus coupling the first digital signal processing unit to the second digital signal processing unit, wherein the first digital signal processing unit further stores a expected result address corresponding to a location of the expected result in the second digital signal processing unit, wherein the first digital signal processing unit conveys the expected result address to the second digital signal processing unit over the address bus, and wherein the integrated circuit determines whether an error has occurred based on the comparison or the received expected result address.

18. The control module of claim 14, wherein the first digital signal processing unit conveys a counter value to the second digital signal processing unit, wherein the second digital signal processing unit further comprises a counter that counts down based on the counter value, and wherein the second digital signal processing unit further determines that an error has occurred when the counter counts down to zero prior to the second digital signal processing unit receiving the verification set output value from the first digital signal processing unit.

19. The control module of claim 14, wherein the first digital signal processing unit stores a first state value and the second digital signal processing unit stores a second state value, wherein each of the first state value and the second state value correspond to a state of the verification process, wherein the second digital signal processing unit retrieves the seed value based upon the second state value.

20. The control module of claim 19, further comprising a data bus and an address bus that each couple the first digital signal processing unit to second digital signal processing unit, wherein the first digital signal processing unit further stores a seed value address corresponding to a location of the seed value in the second digital signal processing unit and conveys the seed value address to the second digital signal processing unit via the address bus, wherein the second digital signal processing unit conveys the seed value via the data bus to the first digital signal processing unit in response to receiving the seed value address and increments the second state value upon conveying the seed value, wherein the first digital signal processing unit increments the first state value upon receiving the seed value, wherein the first digital signal processing unit further increments the first stare value upon conveying the verification set output value to the second digital signal processing unit to produce a twice incremented first state value, and wherein the second digital signal processing unit further increments the second state value upon receiving the verification set output value from the first digital signal processing unit to produce a twice incremented second state value.