Structure for detecting clock gating opportunities in a pipelined electronic circuit design

• US 8,244,515 B2
• Filed: 12/31/2008
• Issued: 08/14/2012
• Est. Priority Date: 08/21/2007
• Status: Active Grant

• Current Assignee: Siemens Industry Software Limited (Siemens AG)
• Original Assignee: International Business Machines Corporation
• Inventors: Fernsler, Matthew Earl, Jacobson, Hans Mikael, Srouji, Johny, Swanson, Todd
• Primary Examiner(s): FREJD, RUSSELL WARREN
• Application Number:
  US12/347,968
• Publication Number:
  US 20090217068A1
• Time in Patent Office: 1,322 Days
• Field of Search: 703 13- 19, 713/320, 712/E9.046, 712/E9.062, 712/E9.063
• US Class Current: 703/18
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3237 by disabling clock generation or distribution
• CPC Class Codes: G06F 2119/06 Power analysis or power optimisation
• CPC Class Codes: G06F 30/327 Logic synthesis; Behaviour synthesis, e.g. mapping logic, HDL to netlist, high-level language to RTL or netlist
• CPC Class Codes: G06F 9/3869 Implementation aspects, e.g. pipeline latches; pipeline synchronisation and clocking
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A design structure for a pipeline electronic processor device may be embodied in a machine readable medium for designing, manufacturing or testing a processor integrated circuit. The design structure may embody a pipeline electronic circuit that enables power conservation in the stages of the pipeline via a simulation that identifies clock-gating opportunities among the stages of the pipeline. In one embodiment, simulation results assist a designer in the design of the pipeline electronic circuit design structure to achieve power conservation by incorporating clock-gating circuitry among the stages of the pipeline at clock gating opportunity locations that the simulation identifies.

Claims

1. A design structure embodied in a nontransitory machine readable medium for designing, manufacturing, or testing an integrated circuit, the design structure comprising:

a pipeline electronic processor device including a plurality of pipeline stages, the plurality of pipeline stages including first and second pipeline stages that each include logic elements that may be clock-gated, each pipeline stage supplying information to a downstream pipeline stage, wherein selected logic elements are clock-gated based on simulation results of a simulation of the pipeline electronic processor device, the simulation specifying the selected logic elements that may be clock-gated under predetermined conditions to achieve power conservation in an information handling system (IHS), the simulation including looking upstream and downstream in the plurality of pipeline stages to determine the selected logic elements that may provide clock gating opportunities, each clock gating opportunity corresponding to a respective clock gating opportunity type, wherein the simulation provides simulation results and further wherein the simulation includes weighting the selected logic elements according to their respective clock gating opportunity types, thus indicating their respective power savings potential when clock gated, thus providing weighted results included in the simulation results.

2. The design structure of claim 1, wherein the simulation includes analyzing the second pipeline stage for clock-gating opportunities by monitoring the first pipeline stage for first pipeline logic elements that do not change logic state from clock cycle to clock cycle.

3. The design structure of claim 1, wherein the simulation includes analyzing the second pipeline stage for clock-gating opportunities by monitoring the first pipeline stage for first pipeline logic elements that are already clock-gated from clock cycle to clock cycle.

4. The design structure of claim 1, wherein the simulation includes analyzing the first pipeline stage for clock-gating opportunities by monitoring the second pipeline stage for first pipeline logic elements that do not change logic state from clock cycle to clock cycle.

5. The design structure of claim 1, wherein the design structure is a netlist.

6. The design structure of claim 1, wherein the design structure resides on a storage medium as a data format used for the exchange of layout data of integrated circuits.

7. A hardware description language (HDL) design structure encoded on a machine-readable data storage medium, said HDL design structure comprising elements that when processed in a computer-aided design system generates a machine-executable representation of a pipeline electronic processor device, wherein said HDL design structure comprises:

a first element processed to generate a functional computer-simulated representation of the pipeline electronic processor device including a plurality of pipeline stages, the plurality of pipeline stages including first and second pipeline stages that each include logic elements that may be clock-gated, each pipeline stage supplying information to a downstream pipeline stage, wherein selected logic elements are clock-gated based on simulation results of a simulation of the pipeline electronic processor device, the simulation specifying the selected logic elements that may be clock-gated under predetermined conditions to achieve power conservation in an information handling system (IHS), the simulation including looking upstream and downstream in the plurality of pipeline stages to determine the selected logic elements that may provide clock gating opportunities, each clock gating opportunity corresponding to a respective clock gating opportunity type, wherein the simulation provides simulation results and further wherein the simulation includes weighting the selected logic elements according to their respective clock gating opportunity types, thus indicating their respective power savings potential when clock gated, thus providing weighted results included in the simulation results.

8. The HDL design structure of claim 7, wherein the simulation includes analyzing the second pipeline stage for clock-gating opportunities by monitoring the first pipeline stage for first pipeline logic elements that do not change logic state from clock cycle to clock cycle.

9. The HDL design structure of claim 7, wherein the simulation includes analyzing the second pipeline stage for clock-gating opportunities by monitoring the first pipeline stage for first pipeline logic elements that are already clock-gated from clock cycle to clock cycle.

10. The HDL design structure of claim 7, wherein the simulation includes analyzing the first pipeline stage for clock-gating opportunities by monitoring the second pipeline stage for first pipeline logic elements that do not change logic state from clock cycle to clock cycle.

11. The HDL design structure of claim 7, wherein the design structure is a netlist.

12. The HDL design structure of claim 7, wherein the design structure resides on a storage medium as a data format used for the exchange of layout data of integrated circuits.

13. A method in a computer-aided design system for generating a functional design model of a pipeline electronic processor device, the method comprising:

generating a functional computer-simulated representation of the pipeline electronic processor device including a plurality of pipeline stages, the plurality of pipeline stages including first and second pipeline stages that each include logic elements that may be clock-gated, each pipeline stage supplying information to a downstream pipeline stage, wherein selected logic elements are clock-gated based on simulation results of a simulation of the pipeline electronic processor device, the simulation specifying the selected logic elements that may be clock-gated under predetermined conditions to achieve power conservation in an information handling system, the simulation including looking upstream and downstream in the plurality of pipeline stages to determine the selected logic elements that may provide clock gating opportunities, each clock gating opportunity corresponding to a respective clock gating opportunity type, wherein the simulation provides simulation results and further wherein the simulation includes weighting the selected logic elements according to their respective power clock gating opportunity types, thus indicating their respective savings potential when clock gated, thus providing weighted results included in the simulation results.

14. The method of claim 13, wherein the simulation includes analyzing the second pipeline stage for clock-gating opportunities by monitoring the first pipeline stage for first pipeline logic elements that do not change logic state from clock cycle to clock cycle.

15. The method of claim 13, wherein the simulation includes analyzing the second pipeline stage for clock-gating opportunities by monitoring the first pipeline stage for first pipeline logic elements that are already clock-gated from clock cycle to clock cycle.

16. The method of claim 13, wherein the simulation includes analyzing the first pipeline stage for clock-gating opportunities by monitoring the second pipeline stage for first pipeline logic elements that do not change logic state from clock cycle to clock cycle.

17. The method of claim 13, wherein the design structure is a netlist.

18. The method of claim 13, wherein the design structure resides on a storage medium as a data format used for the exchange of layout data of integrated circuits.