Design verification system for avoiding false failures and method therefor

A method of verifying functional similarity between a first design and a second design intended to satisfy functionality of the first design, comprising:

• receiving a representation of the first design;
• receiving a representation of the second design;
• receiving a plurality of design inputs;
• executing a test program on a computer that compares the representation of the second design with the representation of the first design, and detecting when the representation of the second design does not satisfy the representation of the first design, the test program providing a failure indicator and a characterization of a failure in response to the detecting, the test program further comprising:
• applying one or more constraints to the characterization of the failure, the one or more constraints representing restrictions on permissible test parameters of the second design representation, and analyzing the failure by determining whether the one or more constraints will prevent the failure from occurring.

A computer readable storage medium for storing a verification system, comprising:

• a set of instructions, the set of instructions when executed implementing a verification process comprising:
• receiving a representation of a first design representing a specification having a predetermined functionality;
• receiving a representation of a second design, the representation of the second design intended to satisfy the predetermined functionality of the first design, the verification system functioning to affirm that the representation of the second design does in fact satisfy the predetermined functionality of the representation of the first design;
• receiving a plurality of design inputs;
• comparing the representation of the second design with the representation of the first design, and detecting when the representation of the second design does not satisfy the representation of the first design, the detecting resulting in providing a failure indicator and a characterization of a failure;
• and
• applying one or more constraints to the characterization of the failure, the one or more constraints representing restrictions on permissible test parameters of the second design representation, and determining whether the one or more constraints will prevent the failure from occurring.

A verification system, comprising:

• a representation of a first design representing a specification having a predetermined functionality;
• a representation of a second design, the representation of the second design intended to satisfy the predetermined functionality of the first design, the verification system functioning to affirm that the representation of the second design does in fact satisfy the predetermined functionality of the representation of the first design;
• a plurality of design inputs;
• a tester for comparing the representation of the second design with the representation of the first design, and detecting when the representation of the second design does not satisfy the representation of the first design, the tester providing a failure indicator and a characterization of a failure in response to the detecting, the tester further comprising:
• a symbolic stimulus generator that analyzes the representation of the first design to determine a set of inputs to a test point and generates a set of symbolic stimulus to be applied to corresponding test point inputs in the representation of the second design, the tester accepting as an additional input one or more additional nodes in the first design, finding additional inputs corresponding to the additional nodes, generating a second set of symbolic stimulus from the additional inputs, applying the second set of symbolic stimulus to corresponding inputs in the representation of the second design, and generating an output response for use in verifying functional similarity.

A method of verifying functional similarity between a first design and a second design intended to satisfy functionality of the first design, comprising:

• receiving a representation of the first design;
• receiving a representation of the second design;
• receiving a plurality of design inputs;
• comparing the representation of the second design with the representation of the first design, detecting when the representation of the second design does not satisfy the representation of the first design, and providing a failure indicator and a characterization of a failure in response to the detecting;
• analyzing with a symbolic stimulus generator the representation of the first design to determine a set of inputs to a test point;
• generating a set of symbolic stimulus to be applied to corresponding test point inputs in the representation of the second design;
• accepting as an additional input one or more additional nodes in the first design;
• finding additional inputs in the first design corresponding to the additional nodes;
• generating a second set of symbolic stimulus from the additional inputs;
• and
• applying the second set of symbolic stimulus to corresponding inputs in the representation of the second design and generating an output response for use in verifying functional similarity.

A computer readable storage medium for storing a verification system, comprising:

• a set of instructions, the set of instructions when executed implementing a verification process comprising:
• receiving a representation of the first design;
• receiving a representation of the second design;
• receiving a plurality of design inputs;
• comparing the representation of the second design with the representation of the first design, detecting when the representation of the second design does not satisfy the representation of the first design, and providing a failure indicator and a characterization of a failure in response to the detecting;
• analyzing with a symbolic stimulus generator the representation of the first design to determine a set of inputs to a test point;
• generating a set of symbolic stimulus to be applied to corresponding test point inputs in the representation of the second design;
• accepting as an additional input one or more additional nodes in the first design;
• finding additional inputs in the first design corresponding to the additional nodes;
• generating a second set of symbolic stimulus from the additional inputs;
• and
• applying the second set of symbolic stimulus to corresponding inputs in the representation of the second design and generating an output response for use in verifying functional similarity.