Simulator and computer-readable recordable medium having program for execution on computer realizing the simulator recorded thereon

• US 6,370,494 B1
• Filed: 02/01/1999
• Issued: 04/09/2002
• Est. Priority Date: 02/05/1998
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Takahashi, Hiroshi, Mizuno, Masanobu
• Primary Examiner(s): FREJD, RUSSELL WARREN
• Application Number:
  US09/241,261
• Time in Patent Office: 1,163 Days
• Field of Search: 703/17, 703/13, 703/14, 703/15, 703/21, 703/19, 714/724, 714/741, 716/4
• US Class Current: 703/17
• CPC Class Codes: G06F 30/33 Design verification, e.g. functional simulation or model checking

Abstract

A simulator capable of counting a number of events occurring in each of functional modules constituting an LSI and calculating an index value for selecting a simulation method for each functional module in simulation of an operation of the LSI with a first test vector set. The simulator further capable of selecting one simulation method among a plurality of simulation methods for each functional module based on the selection index value, and of controlling execution of simulation of the LSI operation with a second test vector set in the simulation method selected for each functional module.

Claims

1. A simulator comprising:

means for counting a number of events occurring in each of functional modules constituting an LSI and means for calculating an index value for selecting a simulation method for each functional module in a particular simulation of an operation of the LSI with a first test vector set;

means for selecting one simulation method among a plurality of simulation methods for each functional module based on the selection index value; and

means for controlling execution of simulation of the LSI operation with a second test vector set in the simulation method selected for each functional module.

2. The simulator according to claim 1, wherein the plurality of simulation methods comprise:

a cycle simulation method in which the functional modules are simulated in a clock signal cycle; and

an event-driven simulation method in which the functional modules are simulated in an event-driven manner.

3. The simulator according to claim 1, wherein the number of events that has been counted during a predetermined period of time is used as the selection index value.

4. The simulator according to claim 1, wherein an event incident rate obtained by dividing the counted number of events by a product of a circuit scale of a functional module and a simulation unit time is used as the selection index value.

5. The simulator according to claim 1, wherein the control means controls such that:

the simulation with the second test vector set is stopped temporarily after a predetermined period of time has lapsed;

the selection index value is re-calculated;

the simulation method for each functional module is selected among the plurality of simulation methods based on the recalculated selection index value; and

the simulation of the LSI operation with the second test vector set that has been stopped temporarily is resumed.

6. The simulator according to claim 5, wherein the selection index value calculating means counts the number of event only with respect to an input signal.

7. The simulator according to claim 5, wherein the selection index value calculating means counts the number of event only with respect to a clock signal.

8. A computer-readable recordable medium having a program for execution on a computer recorded thereon,

the program comprising steps of:

counting a number of events occurring in each of functional modules constituting an LSI so as to calculate an index value for selecting a simulation method for each functional module in a particular simulation of an operation of the LSI with a first test vector set;

selecting one simulation method among a plurality of simulation methods for each functional module based on the selection index value; and

simulating the LSI operation with a second test vector set in the simulation method selected for each functional module.