APPARATUS AND METHOD FOR VALIDATING THE INTEGRITY OF CONTROL SIGNALS IN TIMING DOMAIN

• US 20160062331A1
• Filed: 08/27/2014
• Published: 03/03/2016
• Est. Priority Date: 08/27/2014
• Status: Abandoned Application

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: VON WENDORFF, WILHARD CHRISTOPHORUS
• Application Number:
  US14/469,740
• Publication Number:
  US 20160062331A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G05B 19/042 using digital processors G05B19/05 takes precedence
• CPC Class Codes: G05B 2219/23464 Use signatures to know module is not corrupt, cfc, control flow checking

Abstract

The present application relates to a signal integrity module for validating one or more control signals in time domain and a method thereof. The one or more control signals are received via a signal input from at least one control signal generating unit. A new signature is generated by a signature generating unit on the basis of a current signature and the state of the one or more control signals at a watch point. The current signature is latched into a signature register upon receiving a trigger signal. The latched signature is representative of the time course of the one or more control signals at the watch point over a monitoring period defined by the trigger signal. The latched signature is compared by a signature comparator with a pre-calculated signature to validate the integrity of the one or more control signals with respect to the time domain.

Claims

1. A signal integrity module for validating one or more control signals in time domain, comprising:

a signal input to receive the one or more control signals, wherein the one or more control signals are received from at least one control signal generating unit, wherein the one or more control signals are changing in time;

a watch point generating unit configured to generate watch point signals;

a signature generating unit operably coupled to the signal input to receive the one or more control signals and the watch point generating unit, wherein the signature generating unit is configured to generate a new signature on the basis of a current signature and the state of the one or more control signals at a watch point signalized by the watch point signal;

a signature register operably coupled to the signature generating unit and configured to latch the current signature upon receiving a trigger signal thereat, wherein the latched signature is representative of the time course of the one or more control signals at the watch point over a monitoring period defined by the trigger signal; and

a signature comparator operatively coupled to the signature register and configured to compare the latched signature with a pre-calculated signature to validate the integrity of the one or more control signals with respect to the time domain.

2. The signal integrity module according to claim 1, further comprising:

a watch point counter operatively coupled to the watch point generating unit and configured to count the watch point signals generated thereby.

3. The signal integrity module according to claim 2, further comprising:

a counter register operatively coupled to the watch point counter and configured to latch the current value of the watch point counter upon receiving the trigger signal thereat.

4. The signal integrity module according to claim 1, further comprising:

an input comparator operatively coupled to the signal input and configured to compare current states of the one or more control signals with states of the one or more control signals latched previously to detect whether the states of the one or more control signals have been changed.

5. The signal integrity module according to claim 4, further comprising:

a constant counter operatively coupled to the input comparator and configured to count each detection of unchanged states of the one or more control signals by the input comparator.

6. The signal integrity module according to claim 1, further comprising:

a watchdog operably coupled to the watch point generating unit and configured to generate a fault signal in case the watch point generating unit does not generate a next watch point signal within a predefined period of time.

7. The signal integrity module according to claim 1,

wherein the signature generating unit is configured to generate a real-time signature based on the current signature and the state of the one or more control signals at the watch point.

8. The signal integrity module according to claim 1,

wherein the one or more control signals are dual-value signals.

9. The signal integrity module according to claim 1,

wherein the watch point generating unit is configured to generate a clock signal to signalize the watch points.

10. The signal integrity module according to claim 9,

wherein the watch point generating unit is pre-scaler, which is configured to receive a clock signal and to scale the frequency of the received clock signal by a predefined factor, wherein the pre-scaler is configurable to allow adapting the predefined factor to a periodicity of the one or more control signals.

11. The signal integrity module according to claim 9,

wherein the watch point generating unit is clock signal generator, which is configured to generate the clock signal at a predefined frequency, wherein the clock signal generator is configurable to allow adapting the predefined frequency to a periodicity of the one or more control signals.

12. The signal integrity module according to claim 1,

wherein the signature generating unit is a multiple input signature register and the watch point signal is a shift signal, which is supplied to the multiple input signature register.

13. The signal integrity module according to claim 1,

wherein the one or more control signals are deterministic and periodic in time.

14. A method for validating the integrity of one or more control signals in time domain, comprising:

receiving the one or more control signals via a signal input from at least one control signal generating unit, wherein the one or more control signals are changing in time;

providing, by a watch point generating unit, watch point signals;

generating, by a signature generating unit, a new signature on the basis of a current signature and the state of the one or more control signals at a watch point signalized by the watch point signal;

latching the current signature into a signature register upon receiving a trigger signal thereat, wherein the latched signature is representative of the time course of the one or more control signals at the watch point over a monitoring period defined by the trigger signal; and

comparing, by a signature comparator, the latched signature with a pre-calculated signature to validate the integrity of the one or more control signals with respect to the time domain.

15. The method according to claim 14, further comprising:

counting, by a watch point counter, the watch point signals generated by the watch point generating unit.

16. The method according to claim 15, further comprising:

latching the current value of the watch point counter into a counter register upon receiving the trigger signal thereat.

17. The method according to claim 14, further comprising:

comparing, by an input comparator, current states of the one or more control signals with states of the one or more control signals latched previously to detect whether the states of the one or more control signals have been changed.

18. The method according to claim 17, further comprising:

counting, by a constant counter, each detection of unchanged states of the one or more control signals.

19. The method according to claim 14, further comprising:

generating, by a watchdog, a fault signal in case a next watch point signal is not generated by the watch dog generating unit within a predefined period of time.