Granted Patent B2

US 8,010,935 · App. 12/248,016 · Granted Aug 30, 2011

Abstract

Claims (32)

1. An electronic design automation tool for optimizing a placement of process monitors in an integrated circuit, comprising:

a critical path/cell identifier configured to identify critical paths and critical cells in said integrated circuit, wherein said critical paths are signal paths that exhibit a highest delay and are most sensitive to excessive variations in supply voltage;

a candidate process monitor position identifier coupled to said critical path/cell identifier and configured to identify a set of candidate positions for said process monitors, wherein said process monitors are circuits configured to measure signal propagation speed in nearby cells;

a cluster generator coupled to said critical path/cell identifier and configured to associate said critical cells to form clusters thereof; and

a process monitor placement optimizer coupled to said candidate process monitor position identifier and said cluster generator and configured to place a process monitor within each of said clusters and near said critical paths/cells by selecting among said candidate positions.

2. The electronic design automation tool as recited in claim 1 wherein said critical path/cell identifier operates on said integrated circuit one block at a time, said block being a clock domain of said integrated circuit.

3. The electronic design automation tool as recited in claim 1 wherein said candidate position identifier identifies a fine grid set of positions at which said process monitors may be located.

4. The electronic design automation tool as recited in claim 1 wherein said clusters are of a same area and shape.

5. The electronic design automation tool as recited in claim 1 wherein said process monitor placement optimizer selects a best position based on a quality function.

6. The electronic design automation tool as recited in claim 5 wherein said quality function relates average distances between a candidate position and critical cells in said cluster.

7. The electronic design automation tool as recited in claim 1 wherein said electronic design automation tool is configured to couple said process monitors to a voltage management unit of said integrated circuit.

8. A non-transitory computer-readable medium containing program code which, when executed by a processor of a computer, causes said processor to perform a method of optimizing a placement of process monitors in an integrated circuit, said method comprising:

identifying critical paths and critical cells in said integrated circuit, wherein said critical paths are signal paths that exhibit a highest delay and are most sensitive to excessive variations in supply voltage;

identifying a set of candidate positions for said process monitors, wherein said process monitors are circuits configured to measure signal propagation speed in nearby cells;

associating said critical cells to form clusters thereof; and

placing a process monitor within each of said clusters and near said critical paths/cells by selecting among said candidate positions.

9. The method as recited in claim 8 wherein said method is carried out on said integrated circuit one block at a time, said block being a clock domain of said integrated circuit.

10. The method as recited in claim 8 wherein said identifying said set of candidate positions comprises identifying a fine grid set of positions at which said process monitors may be located.

11. The method as recited in claim 8 wherein said clusters are of a same area and shape.

12. The method as recited in claim 8 wherein said placing comprises selecting a best position based on a quality function.

13. The method as recited in claim 12 wherein said quality function relates average distances between a candidate position and critical cells in said cluster.

14. The method as recited in claim 8 further comprising coupling said process monitors to a voltage management unit of said integrated circuit.

15. An electronic design automation tool for optimizing a placement of process monitors in an integrated circuit, comprising:

a critical path/cell identifier configured to identify critical paths and critical cells in a block of said integrated circuit, wherein said critical paths are signal paths that exhibit a highest delay and are most sensitive to excessive variations in supply voltage;

a candidate process monitor position identifier coupled to said critical path/cell identifier and configured to identify a set of candidate positions in said block for said process monitors, wherein said process monitors are circuits configured to measure signal propagation speed in nearby cells;

a cluster generator coupled to said critical path/cell identifier and configured to associate said critical cells to form clusters thereof; and

a process monitor placement optimizer coupled to said candidate process monitor position identifier and said cluster generator and configured to place a process monitor within each of said clusters and near said critical paths/cells by selecting among said candidate positions based on a quality function.

16. The electronic design automation tool as recited in claim 15 wherein said candidate position identifier identifies a fine grid set of positions at which said process monitors may be located.

17. The electronic design automation tool as recited in claim 15 wherein said clusters are of a same area and shape.

18. The electronic design automation tool as recited in claim 15 wherein said quality function relates average distances between a candidate position and critical cells in said cluster.

19. The electronic design automation tool as recited in claim 15 wherein said electronic design automation tool is configured to couple said process monitors to a voltage management unit of said integrated circuit.

20. The electronic design automation tool as recited in claim 15 wherein said electronic design automation tool is embodied in program code stored on a non-transitory computer-readable storage device.

Assignments (9)