Computer process for interconnecting logic circuits utilizing softwire statements

• US 5,315,534 A
• Filed: 06/25/1991
• Issued: 05/24/1994
• Est. Priority Date: 06/25/1991
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Unisys Corporation
• Inventors: Schlachet, Eli S.
• Primary Examiner(s): Trans, Vincent N.
• Application Number:
  US07/720,356
• Time in Patent Office: 1,064 Days
• Field of Search: 364/488, 364/489, 364/490, 364/491
• US Class Current: 716/129
• CPC Class Codes: G06F 30/394 Routing G06F30/396 takes precedence

Abstract

A computer process interconnects logic circuit on an integrated circuit substrate by generating a single softwire statement for each interconnection, and by thereafter utilizing the softwire statements to generate multiple physical layouts for each interconnection. A "softwire statement" is a computer-generated statement which specifies and establishes a route for an interconnection from one terminal of a logic circuit to another terminal as a series of conductive segments which extend in certain directions between relative jog points that are referenced to blockages such as the logic circuits, on the substrate.

Claims

1. A computer process for interconnecting logic circuits on an integrated circuit substrate;

said process including the steps of;

providing a set of files for said computer which identify--a) blockages, including said logic circuits and pre-existing interconnections on said substrate, b) terminals on said logic circuits that are to be interconnected, and c) a set of layout parameters;

finding, via said computer, an open space on said substrate which goes from one of said terminals to another;

locating, via said computer, relative jog points in said open space with the location of each jog point being established in terms of said layout parameters relative to a respective blockage such that said jog points move as their respective blockage move and/or layout parameters change; and

,

generating, via said computer, a softwire statement that specifies an interconnection from said one terminal to said another terminal as a series of conductor segments which extend in certain directions from said jog points and which stretch/contract as said blockages and jog points move.

2. A process according to claim 1 and further including the step of visually displaying one particular layout of said conductor segments on said substrate.

3. A process according to claim 2 and further including the steps of moving said blockages and respective jog points on said substrate without changing said softwire statement, and visually displaying another layout of said conductor segments.

4. A process according to claim 1 wherein said locating step includes the substep of limiting the total number of blockages to which said jog points are referenced to be approximately one-half the total number of jog points.

5. A process according to claim 4 wherein said locating step includes the substep of referencing said jog points to just two particular corners in said blockages.

6. A process according to claim 5 wherein said two particular corners are a top right corner and a bottom right corner.

7. A process according to claim 5 wherein said two particular corners are a top left corner and a bottom left corner.

8. A process according to claim 4 and further including the step of visually displaying one particular layout of said conductor segments on said substrate.

9. A process according to claim 8 and further including the step of moving said blockages and respective jog points on said substrate without changing said softwire statement, and visually displaying another layout of said conductor segments.

10. A process according to claim 1 and further including the additional steps of incorporating said conductor segments into said blockages, and generating a list of softwire statement by repeating said finding step through said incorporating step on remaining terminals in said file.

11. A process according to claim 10 and further including the step of visually displaying one particular physical layout of said conductor segments for each softwire statement on said list after said list is generated.

12. A process according to claim 10 and further including the step of visually displaying one particular physical layout of said conductor segments each time a softwire statement is generated.