Gene T Wieder

US Patent:

58323104, Nov 3, 1998

Filed:

Feb 4, 1997

Appl. No.:

8/795457

Inventors:

Douglas E. Morrissey - Exton PA
Edward T. Cavanagh - Norristown PA
Gene T. Wieder - Coopersburg PA
Kin H. Ng - Glenmoore PA
William E. Oldham - Pottstown PA

Assignee:

Unisys Corporation - Blue Bell PA

International Classification:

G06F 1300

US Classification:

395891

Abstract:

Apparatus is provided for transferring user defined data from a parallel storage medium to a serial link driver in an I/O channel subsystem of a processor or I/O device controller. The serial link driver transmits a frame of user defined data over a serial data transfer medium. A data buffer receives and stores user defined data from the parallel storage medium. A control data facility that is distinct from the data buffer forms and transmits control data from the sender of the frame to the recipient of the frame via a path that does not include the data buffer. The control data facility includes respectively different dedicated logic for asynchronously generating each of the following: special character sequences, frame delimiters, headers, and cyclic redundancy checksums. A switching facility receives the user defined data from the data buffer. The switching facility also receives control data from the control data facility.

US Patent:

55533027, Sep 3, 1996

Filed:

Dec 30, 1993

Appl. No.:

8/176805

Inventors:

Douglas E. Morrissey - Exton PA
Edward T. Cavanagh - Norristown PA
Gene T. Wieder - Coopersburg PA
Kin H. Ng - Glenmoore PA
William E. Oldham - Pottstown PA

Assignee:

Unisys Corporation - Blue Bell PA

International Classification:

G06F 1300
G06F 1312

US Classification:

395825

Abstract:

An Input/Output (I/O) subsystem is provided for transferring frames containing frame control data from a serial data transfer medium to a parallel storage medium. The subsystem includes independent components for processing different portions of the received character stream. The subsystem includes a sequence recognition mechanism for receiving and identifying any of a plurality of digital data bit sequences. The sequences represent channel status information from the data transfer medium. The sequence recognition mechanism provides an interrupt signal derived from the sequences. A frame recognition mechanism responds to the interrupt signal. The frame recognition mechanism receives and identifies a start-of-frame delimiter or an end-of-frame delimiter from the data transfer medium. The frame recognition mechanism provides a frame status signal. A frame receiving mechanism responds to the frame status signal.