Active path extraction for HDL code

An active forward search method for hardware description language (HDL) code in a computer system, the computer system comprising user input equipment for accepting input from a user, and user output equipment for providing output to the user, the HDL code being used to represent an electronic circuit having a plurality of components, each component having at least an input signal and an output signal, the method comprising:

• utilizing the user input equipment to obtain at least a start signal from the user, the at least a start signal being an input signal;
• utilizing the user input equipment to obtain a start time;
• obtaining simulation results of the electronic circuit from a simulator that utilizes the HDL code, the simulation results having state changes of the output signals and the input signals;
• parsing the HDL code to obtain a circuit connection graph fanning out from the at least a start signal, the connection graph comprising components, input signals, and output signals;
• iterating a forward search method comprising:
• obtaining an active input signal;
• utilizing the connection graph to obtain a connected component, the connected component having the active input signal as an input signal of the connected corn ponent;
• utilizing the HDL code and the simulation results to obtain an execution path of the connected component at an execution time that is on or after the start time;
• and
• utilizing the execution path to determine if an output signal of the connected component is an active output signal of the connected component, wherein the output signal of the connected component is an active output signal of the connected component only if the output signal of the connected component obtains a state in response to a state change of the active input signal;
• wherein the active output signal of the connected component is utilized as an active input signal in a subsequent iteration of the forward search method, and
• any component in the connection graph having an active output signal is an active component;
• wherein the first iteration of the forward search method utilizes the at least a start signal as the active input signal;
• and
• utilizing the user output equipment to provide the active components or the active output signals to the user.

An active backward search method for hardware description language (HDL) code in a computer system, the computer system comprising user input equipment for accepting input from a user, and user output equipment for providing output to the user, the HDL code being used to represent an electronic circuit having a plurality of components, each component having at least an input signal and an output signal, the method comprising:

• utilizing the user input equipment to obtain at least a stop signal from the user, the at least a stop signal being an output signal;
• utilizing the user input equipment to obtain a stop time;
• obtaining simulation results of the electronic circuit from a simulator that utilizes the HDL code, the simulation results having state changes of the output signals and the input signals;
• parsing the HDL code to obtain a circuit connection graph fanning into the at least a stop signal, the connection graph comprising components, input signals, and output signals;
• iterating a backward search method comprising:
• obtaining a start-point active output signal;
• utilizing the connection graph to obtain a connected component, the connected component having the start-point active output signal as an output signal of the connected component;
• utilizing the HDL code and the simulation results to obtain an execution path of the connected component at an execution time that is on or before the stop time;
• and
• utilizing the execution path to determine if an input signal of the connected component is an active input signal of the connected component, wherein the input signal of the connected component is an active input signal of the connected component only if the start-point active output signal obtains a state in response to a state change of the input signal of the connected component;
• wherein the active input signal of the connected component is utilized as a start-point active output signal in a subsequent iteration of the backward search method;
• wherein the first iteration of the backward search method utilizes the at least a stop signal as the start-point active output signal;
• and
• utilizing the user output equipment to provide the active components, the active output signals, or the active input signals to the user.

A computer system comprising:

• input equipment for obtaining data from a user;
• output equipment for providing data to the user;
• a central processing unit (CPU) for controlling functionality of the computer system;
• and
• a memory comprising program code that is executable by the CPU to direct operations of the CPU, the program code containing instructions for:
• obtaining hardware description language (HDL) code, the HDL code being used to represent an electronic circuit having a plurality of components, each component having at least an input signal and an output signal;
• utilizing the user input equipment to obtain at least a start signal from the user, the at least a start signal being an output signal or an input signal;
• utilizing the user input equipment to obtain at least a stop signal from the user, the at least a stop signal being an output signal or an input signal;
• utilizing the user input equipment to obtain a start time and a stop time;
• obtaining simulation results generated by a simulator according to the HDL code, the simulation results having state changes of the output signals and the input signals;
• parsing the HDL code to obtain a circuit connection graph between the at least a start signal and the at least a stop signal, the connection graph comprising components, input signals, and output signals that electrically connect the at least a start signal to the at least a stop signal;
• utilizing the simulation results and the HDL code to determine which of the components in the circuit connection graph are active components, an active component being any component in the circuit connection graph having an active output signal, an active output signal being any output signal of any component in the circuit connection graph that obtains a state between the start time and the stop time in response to a state change of the at least a start signal according to an execution path of the HDL code;
• and
• utilizing the user output equipment to provide the active components or the active output signals to the user.

A computer system comprising:

• input equipment for obtaining data from a user;
• output equipment for providing data to the user;
• a central processing unit (CPU) for controlling functionality of the computer system;
• and
• a memory comprising program code that is executable by the CPU to direct operations of the CPU, the program code containing instructions for:
• obtaining hardware description language (HDL) code, the HDL code being used to represent an electronic circuit having a plurality of components, each component having at least an input signal and an output signal;
• utilizing the user input equipment to obtain at least a start signal from the user, the at least a start signal being an input signal;
• utilizing the user input equipment to obtain a start time;
• obtaining simulation results generated from a simulator according to the HDL code, the simulation results having state changes of the output signals and the input signals;
• parsing the HDL code to obtain a circuit connection graph fanning out from the at least a start signal, the connection graph comprising components, input signals, and output signals;
• iterating a forward search algorithm contained in the program code having instructions for:
• obtaining an active input signal;
• utilizing the connection graph to obtain a connected component, the connected component having the active input signal as an input signal of the connected corn ponent;
• utilizing the HDL code and the simulation results to obtain an execution path of the connected component at an execution time that is on or after the start time;
• and
• utilizing the execution path to determine if an output signal of the connected component is an active output signal of the connected component, wherein the output signal of the connected component is an active output signal of the connected component only if the output signal of the connected component obtains a state in response to a state change of the active input signal;
• wherein the active output signal of the connected component is utilized as an active input signal in a subsequent iteration of the forward search method, and any component in the connection graph having an active output signal is an active component;
• wherein the first iteration of the forward search algorithm utilizes the at least a start signal as the active input signal;
• and
• utilizing the user output equipment to provide the active components or the active output signals to the user.

A computer system comprising:

• input equipment for obtaining data from a user;
• output equipment for providing data to the user;
• a central processing unit (CPU) for controlling functionality of the computer system;
• and
• a memory comprising program code that is executable by the CPU to direct operations of the CPU, the program code containing instructions for:
• obtaining hardware description language (HDL) code, the HDL code being used to represent an electronic circuit having a plurality of components, each component having at least an input signal and an output signal;
• utilizing the user input equipment to obtain at least a stop signal from the user, the at least a stop signal being an output signal;
• utilizing the user input equipment to obtain a stop time;
• obtaining simulation results of the electronic circuit from a simulator that utilizes the HDL code, the simulation results having state changes of the output signals and the input signals;
• parsing the HDL code to obtain a circuit connection graph fanning into the at least a stop signal, the connection graph comprising components, input signals, and output signals;
• iterating a backward search algorithm comprising:
• obtaining a start-point active output signal;
• utilizing the connection graph to obtain a connected component, the connected component having the start-point active output signal as an output signal of the connected component;
• utilizing the HDL code and the simulation results to obtain an execution path of the connected component at an execution time that is on or before the stop time;
• and
• utilizing the execution path to determine if an input signal of the connected component is an active input signal of the connected component, wherein the input signal of the connected component is an active input signal of the connected component only if the tart-point active output signal obtains a state in response to a state change of the input signal of the connected component;
• wherein the active input signal of the connected component is utilized as a start-point active output signal in a subsequent iteration of the backward search algorithm;
• wherein the first iteration of the backward search algorithm utilizes the at least a stop signal as the start-point active output signal;
• and
• utilizing the user output equipment to provide the active components, the active output signals, or the active input signals to the user.