Interface circuit for interfacing between asynchronous data in start/stop format and synchronous data

Patent 4569062 Issued on February 4, 1986. Estimated Expiration Date:

June 28, 2004. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Receive buffer for converting synchronous-to-asynchronous data
Patent #: 4263673
Issued on: 04/21/1981
Inventor: Bingham , et al.

Digital loop transceiver for interfacing a digital PABX to a digital subscriber set via a subscriber line Patent #: 4432089
Issued on: 02/14/1984
Inventor: Wurzburg , et al.

Inventors

Application

No. 06/625870 filed on 06/28/1984

US Classes:

375/370, With asynchronous data370/305, Start-Stop370/465, Adaptive375/357Synchronization failure prevention

Examiners

Primary: Bookbinder, Marc E.
Assistant: Telesz, A.

International Classes

H04L 5/00 (20060101)
H04L 5/24 (20060101)

Abstract

A data interface circuit for interfacing between an asynchronous data source providing data in start/stop format and a synchronous data communication channel is provided. The data interface circuit has a transmit portion and a receive portion which function independently. Upon receipt of asynchronous data, the transmit portion strips start and stop bits from the data and transmits the data in data frames of variable length characterized by beginning and ending with synchronizing idle codes. The synchronizing idle codes are transmitted in the absence of data to maintain synchronization. A code circuit insures that a data word is never the same as the idle code. Similarly, upon receipt of synchronous data and idle codes, the receive portion stores the data and controllably adds start and stop bits. Data in start/stop format is asynchronously provided at an output of the receive portion.

Other References

Wurzburg; "Proceedings of the National Electronics Conference;" vol. 37; Oct. 24-26, 1983; Marriot Oak Brook Hotel, Oak Brook, Ill.; pp. 501-506
Wurzburg et al.; "PBX-Based LANS: Lower Cost per Terminal Connection;" Reprinted from Computer Design; Feb. 1984