Derating factor determination for integrated circuit logic design tools

• US 7,010,475 B2
• Filed: 02/05/2003
• Issued: 03/07/2006
• Est. Priority Date: 05/03/1999
• Status: Expired due to Fees

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Ehrler, Timothy J.
• Primary Examiner(s): Rodriquez, Paul L.
• Assistant Examiner(s): SHARON, AYAL I
• Application Number:
  US10/358,979
• Publication Number:
  US 20030182098A1
• Time in Patent Office: 1,126 Days
• Field of Search: 703/2, 703 14- 15, 716/4, 716/6, 702/34
• US Class Current: 703/15
• CPC Class Codes: G06F 30/33 Design verification, e.g. functional simulation or model checking

Abstract

An integrated circuit development library is provided that characterizes several different logic device cells. The library specifies a number of different timing relationships for each of the logic device cells. These timing relationships are evaluated for each of the logic device cells at a first derating condition with a first simulator to provide a first set of derated condition values. The first set of derated condition values each correspond to one of the timing relationships evaluated. A first derating factor is calculated from the first set of derated condition values for estimating derated performance of an integrated circuit with a second simulator. This integrated circuit is developed from one or more of the logic device cells of the library.

Claims

1. A method, comprising:

(a) providing an integrated circuit development library characterizing several different logic device cells, the library specifying a number of different timing relationships for each of the logic device cells;

(b) determining a number of derating values for characterizing derated performance of each of the logic device cells, each of the derating values being determined by evaluating a different one of the timing relationships for each of the logic device cell descriptions at a derating condition with a first simulator; and

(c) calculating a number of derating factors, the derating factors each being determined from a different subset of the derated condition values, the derating factors being applicable to estimate derated performance of an integrated circuit developed from the library with a second simulator, the calculating of the number of derating factors including;

establishing a number of best cast multiplier arrays and a number of worst case multiplier arrays; and

screening each of the best case multiplier arrays and each of the worst case multiplier arrays.

2. The method of claim 1, wherein the derating condition corresponds to one of temperature, voltage, or process.

3. The method of claim 1, further comprising evaluating each of the timing relationships for each of the logic device cells at a different derating condition with the first simulator to provide other derated condition values.

4. An apparatus, comprising:

a processing system including;

means for providing a library including a plurality of logic device cell descriptions each including a number of timing relationships;

means for determining a number of derating values for characterizing derated performance of each of the logic device cells, each of the derating values being determined by evaluating a different one of the timing relationships for each of the logic device cell descriptions at a derating condition with a first simulator; and

means for calculating a number of derating factors, the derating factors each being determined from a different subset of the derating values, the derating factors being applicable to estimate derated performance of an integrated circuit developed from the library with a second simulator, and wherein said calculating means includes means for establishing a number of best case multiplier arrays and a number of worst case multiplier arrays and means for screening each of the best case multiplier arrays and each of the worst case multiplier arrays.

5. The apparatus of claim 4, wherein said providing means includes a computer readable medium encoded with said library.

6. The apparatus of claim 4, wherein said calculating means includes a processor operable to execute a derating factor extraction program to calculate said derating factors.