US 7,003,064 B2 · Method and apparatus for periodic phase alignment

Abstract

In one form, apparatus for aligning clock signals includes first and second logic circuitry for receiving respective first and second clock signals. The first and second clock signals are substantially synchronized and operations of the first logic circuitry and second logic circuitry are clocked by the respective first and second clock signals. The first logic circuitry receives a third clock signal derived from the second clock signal, and by repeatedly sampling the third clock signal with the first clock signal, the first logic circuitry repeatedly detects relative phase relations of the first and third clock signals. The second logic circuitry adjusts the phase of the third clock signal responsive to an accumulation of the phase relation detecting.

Claims20

Dependent claims

A method for aligning clock signals, the method comprising the steps of:

a) receiving first and second clock signals by respective first and second logic circuitry, wherein the first and second clock signals are substantially synchronized and operations of the first logic circuitry and second logic circuitry are clocked by the respective first and second clock signals;
b) receiving, by the first logic circuitry, a third clock signal, wherein the third clock signal is derived from the second clock signal;
c) repeatedly sampling the third clock signal with the first clock signal, using the first logic circuitry;
d) detecting relative phase relations of the first and third clock signals repeatedly by the first logic circuitry;
and
e) altering the phase of the third clock signal responsive to an accumulation of the phase relation detecting.

3 more elements

Apparatus for aligning clock signals, the apparatus comprising:

first and second logic circuitry for receiving respective first and second clock signals, wherein the first and second clock signals are substantially synchronized and operations of the first logic circuitry and second logic circuitry are clocked by the respective first and second clock signals, wherein the first logic circuitry receives a third clock signal derived from the second clock signal, and by repeatedly sampling the third clock signal using the first, the first logic circuitry repeatedly detects relative phase relations of the first and third clock signals, and wherein the second logic circuitry adjusts the phase of the third clock signal responsive to an accumulation of the phase relation detecting.

Apparatus for aligning clock signals, the apparatus comprising:

first and second logic circuitry for receiving respective first and second clock signals, wherein the first and second clock signals are substantially synchronized and operations of the first logic circuitry and second logic circuitry are clocked by the respective first and second clock signals, wherein the first logic circuitry includes a state machine, a flip timer, an edge counter and edge detector, and receives a third clock signal derived from the second clock signal, wherein by repeatedly sampling third clock signal with the first, the first logic circuitry repeatedly detects relative phase relations of the first and third clock signals, and wherein the second logic circuitry includes a clock divider and a synchronizer, and the second logic circuitry adjust the phase of the third clock signal responsive to an accumulation of the phase relation detecting, and wherein phase adjustment of the third clock signal comprises latching, for the clock divider, a signal from the synchronizer responsive to a certain edge of the second clock, and phase adjustment of the derived clock signal if the signal from the synchronizer is asserted.

Dependencies are inferred from the claim text.

Method and apparatus for periodic phase alignment

Life of this patent

Method and apparatus for periodic phase alignment

Life of this patent

Abstract

Claims20