Andrew L Caldwell

US Patent:

6526555, Feb 25, 2003

Filed:

Oct 5, 2001

Appl. No.:

09/972556

Inventors:

Steven Teig - Menlo Park CA
Andrew Caldwell - Santa Clara CA

Assignee:

Cadence Design Systems, Inc. - San Jose CA

International Classification:

G06F 1750

US Classification:

716 11, 716 12, 716 13, 716 14

Abstract:

The present invention introduces methods for implementing gridless non Manhattan architecture for integrated circuits. In one particular embodiment, an integrated circuit layout containing horizontal, vertical, and diagonal interconnect lines is first created. Next, the integrated circuit layout is then compacted. The compacting method first creates groups of horizontal and diagonal interconnect lines sorted by vertical position and groups of vertical and diagonal interconnect lines sorted by horizontal position. The two groups are then compacted in a manner that ensures that a minimum manufacturing line spacing requirement is satisfied.

US Patent:

6711727, Mar 23, 2004

Filed:

Jun 3, 2001

Appl. No.:

09/681775

Inventors:

Steven Teig - Menlo Park CA
Andrew Caldwell - Sunnyvale CA

Assignee:

Cadence Design Systems, Inc. - San Jose CA

International Classification:

G06F 1750

US Classification:

716 12, 716 8, 716 9, 716 10, 716 11, 716 13, 257206, 257208, 257300, 257369, 257758

Abstract:

The present invention introduces several methods for implementing integrated circuits that use gridless non Manhattan routing to connect the integrated circuit components. In one embodiment, the non Manhattan routed integrated circuits are created by creating an initial route and then compacting the design down. In another embodiment, a gridless non Manhattan integrated circuits are implemented by adapting a gridless Manhattan routing system into a gridless non Manhattan routing system by rotating a plane of a tile based maze router.

US Patent:

6769105, Jul 27, 2004

Filed:

Oct 5, 2001

Appl. No.:

09/972452

Inventors:

Steven Teig - Menlo Park CA
Andrew Caldwell - Santa Clara CA

Assignee:

Cadence Design Systems, Inc. - San Jose CA

International Classification:

G06F 1750

US Classification:

716 12, 716 5, 716 7, 716 8, 716 10, 716 11

Abstract:

The present invention introduces several methods for implementing non Manhattan routing systems for integrated circuit manufacture. In one embodiment, a non Manhattan routing system is implemented by memorizing where intersections between wiring pitch grids occur and connecting such intersections with vias. In another embodiment, a gridless non Manhattan routing systems may be implemented by adapting a gridless Manhattan routing system by rotating a plane of a tile based maze router.

US Patent:

6829757, Dec 7, 2004

Filed:

Feb 12, 2002

Appl. No.:

10/076121

Inventors:

Steven Teig - Menlo Park CA
Andrew Caldwell - Santa Clara CA

Assignee:

Cadence Design Systems, Inc. - San Jose CA

International Classification:

G06F 1750

US Classification:

716 12, 438737, 716 1, 716 5, 716 13

Abstract:

Some embodiments of the invention provide a method of generating a multi-layer topological path for a layout that has multiple layers. This method specifies a set of path expansions from a first topological item to a second topological item on a first layer of the layout. For a potential via expansion from the second topological item to a third topological item on a second layer of the layout, the method (1) identifies a first region on the first layer for the second topological item, (2) identifies a second region on the second layer the third topological item, (3) determines whether an intersection of the first and second regions is sufficiently large to contain a via, and (4) if the intersection is sufficiently large, adds the potential via expansion to the specified set of path expansions.

US Patent:

6859916, Feb 22, 2005

Filed:

Jan 31, 2002

Appl. No.:

10/062995

Inventors:

Steven Teig - Menlo Park CA, US
Andrew Caldwell - Santa Clara CA, US

Assignee:

Cadence Design Systems, Inc. - San Jose CA

International Classification:

G06F017/50
H01L023/48

US Classification:

716 13, 716 10, 716 14, 257773, 257774

Abstract:

Some embodiments of the invention provide vias that are not in shape of quadrilaterals. In some embodiments, some or all vias are in shape of non-quadrilateral polygons, such as octagons and hexagons. In some embodiments, some or all vias have a circular shape. Some embodiments provide a first set of vias that have a diamond shape and a second set of vias that have a rectangular shape. In some embodiments, a via can also be formed by a diamond contact and a rectangular contact. The diamond contact has four sides. In the embodiments described below, all four sides of a diamond via contact have equal sides. However, in other embodiments, a via contact can be in shape of a diamond with a pair of sides that are longer than the other pair of sides. Similarly, in the embodiments described below, the rectangular via contacts are squares with four equal sides. However, in other embodiments, the length and width of a rectangular via contact can differ.

US Patent:

6877146, Apr 5, 2005

Filed:

Jan 31, 2002

Appl. No.:

10/066187

Inventors:

Steven Teig - Menlo Park CA, US
Andrew Caldwell - Santa Clara CA, US

Assignee:

Cadence Design Systems, Inc. - San Jose CA

International Classification:

G06F017/50

US Classification:

716 12, 716 13, 716 14

Abstract:

One embodiment of the invention is a method of specifying routes for a group of nets. The method specifies a total cost. It then performs a first depth-first search to identify, for the group of nets, a complete routing solution that has a cost that does not exceed the total cost. A routing solution for a set of nets includes a route for each net in the set. If the search does not find the complete routing solution, the method then increments the total cost and performs a second depth-first search to identify a complete routing solution for the group of nets that has a cost that does not exceed the incremented total cost.

US Patent:

6882055, Apr 19, 2005

Filed:

Jan 31, 2002

Appl. No.:

10/066047

Inventors:

Steven Teig - Menlo Park CA, US
Andrew Caldwell - Santa Clara CA, US

Assignee:

Cadence Design Systems, Inc. - San Jose CA

International Classification:

H01L023/48
H01L023/52
H01L029/40

US Classification:

257774, 438640

Abstract:

Some embodiments of the invention provide vias that are not in shape of quadrilaterals. In some embodiments, some or all vias are in shape of non-quadrilateral polygons, such as octagons and hexagons. In some embodiments, some or all vias have a circular shape. Some embodiments provide a first set of vias that have a diamond shape and a second set of vias that have a rectangular shape. In some embodiments, a via can also be formed by a diamond contact and a rectangular contact. The diamond contact has four sides. In the embodiments described below, all four sides of a diamond via contact have equal sides. However, in other embodiments, a via contact can be in shape of a diamond with a pair of sides that are longer than the other pair of sides. Similarly, in the embodiments described below, the rectangular via contacts are squares with four equal sides. However, in other embodiments, the length and width of a rectangular via contact can differ.

US Patent:

6886149, Apr 26, 2005

Filed:

Oct 31, 2002

Appl. No.:

10/286584

Inventors:

Steven Teig - Menlo Park CA, US
Andrew Caldwell - Santa Clara CA, US

Assignee:

Cadence Design Systems, Inc. - San Jose CA

International Classification:

G06F017/50

US Classification:

716 12, 716 13, 716 14, 716 15

Abstract:

Some embodiments of the invention provide a method of routing a set of nets. The method specifies a first order for the set of nets. It then routes the nets according to the specified first order. The method then specifies a second order for the set of nets, where the second order has the fewest possible number of differences with the first order. The method then routes the nets according to the specified second order.