Fast change standard cell digital logic chip

US5214299A · kind A · utility

Assignee

• Unisys Corporation · US

Inventors

• Laszlo V. Gal · Poway, US
• David W. Waite · Carlsbad, US
• Jonathan Levi · Fallbrook, US

Key dates

• Filing date: Sep 22, 1989
• Grant date: May 25, 1993
• Expiry date: Sep 22, 2009

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D89/10

Abstract

An improved standard cell logic chip, of the type which contains one to fifteen thousand standard logic cells that are disposed in rows on a substrate, and has cell interconnect channels of different widths between the rows, also includes fast change logic cells which are sparsely distributed in the rows of standard logic cells. Each fast change cell selectively performs any one of several logic functions. These fast change logic cells are formed from the same stacked conductive and insulative layers as the standard logic cells; however, in the fast change cells, all conductive and insulative layers which are below at least the mid level in the stack of layers have respective patterns which are identical in every fast change cell. Only the remaining conductive and insulative layers in the fast change cells have respective patterns which differ from one fast change cell to another, and they select the logical functions which the fast change cells perform.