Patent · US Expired

Mask-programmable logic device with programmable input/output ports

US7304496B2 · kind B2 · utility

1Cited by
5References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 28, 2005
Grant dateDec 4, 2007
Priority date
Expiry dateAug 3, 2025

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K19/17796
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A mask-programmable logic device includes a macrocell having an external input/output port for “place-and-route” programming by addition of metallization layers. A programmable “fixed” layer allows the external input/output port to be isolated from the remainder of the macrocell so that it “floats,” allowing signals to be routed through the external input/output port when the macrocell is not in use, to reduce routing blockages. The macrocell also may have at least one internal input/output port, potentially connected to different logic circuits, and a programmable “fixed” layer that can be used to control which internal input/output port is connected to the external input/output port. By thus allowing multiple logic circuits to share a single external input/output port, routing blockages are reduced.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.