Patent · US Expired

Circuitry architecture and method for improving output tri-state time

US6028448A · kind A · utility

9Cited by
1References
20Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 27, 1998
Grant dateFeb 22, 2000
Priority date
Expiry dateMar 27, 2018

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K19/09429
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

An output buffer includes a differential data circuit for generating a first and a second differential signal, a pulse circuit for generating a pulse signal, a first latch circuit set by the first differential signal and reset by either the pulse signal or the second differential signal and a second latch circuit set by the second differential signal and reset by either the pulse signal or the first differential signal. An output circuit generates an output signal, the output signal being tri-stated whenever the pulse signal resets the first and second latch circuits. A method for improving output tri-state time of an output buffer includes the steps of pre-charging first and the second differential data inputs; tri-stating the buffer output upon each assertion of a timing signal; switching the output out of tri-state and into either a first or a second logic state only when one of the first and second differential data inputs changes to an active state; and returning to the pre-charging step. As the output of the buffer is tri-stated upon each assertion of the timing signal irrespective of whether a current cycle is a read, write cycle or de-select cycle, the switching time from o…

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