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. 06, 1996
Filed:
Nov. 02, 1992
Brian C Edem, San Jose, CA (US);
Debra J Worsley, Sunnyvale, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A data communication system, such as a local area network, is provided with a capability of transmitting isochronous data. Preferably the system conveys both isochronous data and non-isochronous data by time-multiplexing the data into a recurring frame structure on a four-bit nibble basis. Bandwidth available for a particular isochronous source/sink is selectable and sustainable with a predefined granularity. Data rates can be adjusted by using 'rate adjustment' time slots which can transmit data in some frames and 'no data' in other frames. A particular time frame or template is provided which accommodates isochronous data, non-isochronous data, D channel data, maintenance data and frame synchronization signals. Non-isochronous operation and bandwidth allocation is independent and transparent to the isochronous data activity. Frame timing can be coordinated with one or more reference clock signals, e.g., from a public telephone or wide area network. A buffer can convert between the source/sink or hub circuitry data rates and the data rates for transmission over the physical media which, for a given type of data, is discontinuous on a small time scale.