Patent · US Expired

Circuit and method for stopping a clock tree while maintaining PLL lock

US6624681B1 · kind B1 · utility

12Cited by
6References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 30, 2001
Grant dateSep 23, 2003
Priority date
Expiry dateJul 30, 2021

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02D10/00
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A circuit and method for stopping a clock tree while maintaining PLL lock. A clock circuit includes a locked loop circuit and a clock tree distribution network. The locked loop circuit receives an input clock signal and generates a PLL output clock depending upon a feedback signal. The clock tree is coupled to the locked loop circuit and conveys the PLL output clock to a plurality of clocked circuit elements. The clock circuit further includes a gating circuit and a feedback delay circuit. The gating circuit is coupled between the locked loop circuit the clock tree distribution network and selectively inhibits the PLL output clock from clocking the clock tree distribution network. The feedback delay circuit provides the feedback signal, which represents a delayed version of the PLL output clock, during operation including when the gating circuit inhibits the PLL output clock from clocking the clock tree.

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