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:
Aug. 17, 1999
Filed:
Dec. 18, 1996
Kenji Sakaue, Yokohama, JP;
Masahiko Motoyama, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
An ATM switch having multiple input and output ports is provided. The ATM switch receives ATM cells through the input ports and outputs the ATM cells through one of the output ports in accordance with output port information included in the ATM cells. An output buffer is also provided for each of the output ports to store ATM cells to be output through the output port. A cell counter is provided for each of the output buffers to count the number of ATM cells being stored in the output buffer. Additionally, the ATM switch includes counter verification circuitry for determining whether the cell counters are correctly counting the number of ATM cells stored in the output buffers. In one preferred embodiment, the counter verification circuitry includes a global cell counter that counts the total number of ATM cells being stored in all of the output buffers, an accumulator that determines the total number of ATM cells counted by the cell counters, and a comparator for comparing the accumulated count value with the global count value. Thus, the proper operation of the cell counters can be verified. This minimizes the possibility of improper operation due to a malfunction, even when the ATM switch is operated continuously for a long time period.