US 12,169,420 B2
Timebase synchronization using pulsed signal injection
David Sobel, Los Altos, CA (US); Pieter Kaspenberg, Santa Clara, CA (US); Pierre-Yves Droz, Los Altos, CA (US); and Srikanth Muroor, Mountain View, CA (US)
Assigned to Waymo LLC, Mountain View, CA (US)
Filed by Waymo LLC, Mountain View, CA (US)
Filed on Sep. 25, 2023, as Appl. No. 18/473,591.
Application 18/473,591 is a continuation of application No. 17/647,633, filed on Jan. 11, 2022, granted, now 11,822,377.
Prior Publication US 2024/0012447 A1, Jan. 11, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. G06F 1/12 (2006.01)
CPC G06F 1/12 (2013.01) 20 Claims
OG exemplary drawing
 
1. A method comprising:
determining timestamps upon simultaneous injection of a synchronization pulse into a plurality of processors, wherein the plurality of processors includes a first processor and a second processor, the first processor having a first reference clock, the second processor having a second reference clock, and the first and second reference clocks being off sync from each other, and wherein determining the timestamps includes determining a first timestamp of the simultaneously injected synchronization pulse according to the first reference clock of the first processor and determining a second timestamp of the simultaneously injected synchronization pulse according to the second reference clock of the second processor;
computing a time offset between the first timestamp determined according to the first reference clock of the first processor and the second timestamp determined according to the second reference clock of the second processor; and
using the computed time offset as a basis to provide a synchronized timebase for time measurements thereafter made by the first and second processors.