Patent · US Expired

Dual mode combining circuitry

US5189636A · kind A · utility

58Cited by
4References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 10, 1990
Grant dateFeb 23, 1993
Priority date
Expiry dateDec 10, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F2207/3828
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A video signal processor includes cicuitry which may be conditioned by a mode control signal to operate as a single 16-bit adder or as two eight-bit adders. The circuitry includes two eight-bit adders, each of which has a carry-in input terminal and a carry-out output terminal. The carry-out output terminal of one of the adders is selectively coupled, via an AND gate, to the carry-in input terminal of the other adder. The AND gate is controlled by the mode control signal. In the mode where the circuitry operates as two eight-bit adders, additional circuiry is included to detect output values which may exceed the zero to 255 range of valid values and to saturate these invalid values either at zero or 255.

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