Thomas Thomas Pham

US Patent:

7940878, May 10, 2011

Filed:

Feb 23, 2007

Appl. No.:

11/678256

Inventors:

Steven J. Baumgartner - Zumbro Falls MN, US
Timothy C. Buchholtz - Rochester MN, US
Andrew D. Davies - Rochester MN, US
Thomas W. Liang - Rochester MN, US
Andrew B. Maki - Rochester MN, US
Thomas Pham - Rochester MN, US
Dana M. Woeste - Mantorville MN, US
Daniel G. Young - Rochester MN, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H03D 3/24
H04L 7/00

US Classification:

375376, 375355

Abstract:

A phase locked loop generates an output corresponding to a source synchronous input and an input link clock signal. A phase locking feedback system receives the input and an input link clock signal and detects phase deviations between the output and the input. The phase locking feedback system also adjusts an adjusted clock signal based on the phase deviations thereby causing the phase locking feedback system to generate the output so that the output has a steady phase relationship with the input. A first mechanism causes the phase locking feedback system not to track phase deviations between the output and the input upon occurrence of a first predefined event, thereby maintaining the adjusted clock signal at a current state.