(12) United States Patent ao) Patent No.: us 6,324,671 Bi
Ratzel et al. (45) Date of Patent: *Nov. 27,2001
(54) USING A REDUCED CELL LIBRARY FOR PRELIMINARY SYNTHESIS TO EVALUATE DESIGN
(75) Inventors: Richard L. Ratzel, Westlake, OH (US);
John F. Croix, Round Rock; Stephen
R. King, Austin, both of TX (US)
(73) Assignee: Advanced Micro Devices, Inc.,
Sunnyvale, CA (US)
( * ) Notice: This patent issued on a continued pros-
ecution application filed under 37 CFR
1.53(d), and is subject to the twenty year
patent term provisions of 35 U.S.C.
Subject to any disclaimer, the term of this
patent is extended or adjusted under 35
U.S.C. 154(b) by 152 days.
This patent is subject to a terminal dis-
(21) Appl. No.: 09/343,129
(22) Filed: Jun. 29, 1999
Related U.S. Application Data
(63) Continuation of application No. 08/805,597, filed on Feb. 26, 1997, now Pat. No. 5,956,497.
(51) Int. CI. C06K 17/50
(52) U.S. CI 716/1
(58) Field of Search 395/500.19, 500.06,
395/500.07, 500.34, 500.03, 500.02; 716/1,
2, 5, 6, 18
(56) References Cited
U.S. PATENT DOCUMENTS
5,572,437 * 11/1996 Rostoker et al 395/500.19
A reduced cell library includes substantially fewer cells than a complete cell library used to finalize the integrated circuit design. More particularly, each cell in the reduced cell library may be characterized by a first drive strength which is the same for each cell in the library. The reduced cell library can be used to evaluate the RTL description of an integrated circuit without incurring long synthesis delays. Large problems in the RTL description (with respect to one or more design goals) may be detected, and the RTL description may be modified to correct the problems.
26 Claims, 13 Drawing Sheets