The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 16, 1992
Filed:
Mar. 16, 1990
Junichi Yoshimura, Hino, JP;
Atsuhiko Utsumi, Tachikawa, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A phase synchronization pull-in system used in a bit error detecting apparatus includes a monitored circuit for inputting an input signal and processing the input signal when an operation of the monitored circuit is to be monitored, a standard circuit for processing an output of the monitored circuit inversely to the processing in the monitored circuit, a phase synchronization circuit for inputting the input signal of the monitored circuit and adjusting a first delay time of the input signal so that the first delay time coincides with a second delay time of the output of the standard circuit corresponding to the input signal, a bit error detecting circuit for detecting a difference between the input signal, after being delayed through a variable delay circuit, and the output of the standard circuit, bit by bit, and a controller for controlling the adjusting of the first delay time, a monitoring operation, and a phase synchronization pull-in operation. In the phase synchronization pull-in operation, the first delay time is obtained in the phase synchronization circuit based on whether or not a bit error rate measured by setting the delay time is higher than a predetermined value. The controller determines whether or not more than one possible value of the first delay time enables a successful phase synchronization pull-in, and carries out the monitoring operation when a successful phase synchronization pull-in is successfully carried out for only one value of the first delay time.