[54] INPUT-OUTPUT ELEMENT HAS SELF
TIMED INTERFACE USING A RECEIVED
CLOCK SIGNAL TO INDIVIDUALLY PHASE
ALIGNED BITS RECEIVED FROM A
PARALLEL BUS
[75] Inventors: Robert S. Capowski, Verbank; Daniel
F. Casper, Poughkeepsie; Frederick J.
Cox, Wappingers Falls; Frank D.
Ferraiolo, New Windsor; Marten J.
Halma, Poughquag, all of N.Y.
[73] Assignee: International Business Machines Corporation, Armonk, N.Y.
[21] Appl. No.: 261,561
[22] Filed: Jun. 17, 1994
[51] Int. CI.6 G06F 13/42; G06F 13/00
[52] U.S. CI 395/881; 371/1; 364/271;
364/DIG. 1; 395/550; 370/85.1; 370/105.3
[58] Field of Search 395/275, 550,
395/881; 375/106, 118; 371/1; 370/85.1,
105.3
[56] References Cited
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4,050,097 9/1977 Miu et al 364/200
4,371,962 2/1983 Zeitraeg 370/100
4,694,472 9/1987 Torok et al 375/107
4,771,440 9/1988 Fromin et al 375/52
4,797,951 1/1989 Duxbury et al 455/608
4,914,429 4/1990 Upp 340/825.8
4,965,884 10/1990 Okura et al 375/106
5,022,057 6/1991 Nishi et al 375/119
5,051,990 9/1991 Kato 370/105.3
5,113,385 5/1992 Murakami et al 370/102
5,121,381 6/1992 Takahashi et al 359/117
5,400,370 3/1995 Guo 375/118
FOREIGN PATENT DOCUMENTS
2-166918 6/1990 Japan .
5- 175945 7/1993 Japan .
6- 053955 2/1994 Japan .
Primary Examiner—Thomas C. Lee
Assistant Examiner—Po Huang
Attorney, Agent, or Firm—Lynn L. Augspurger; Laurence J.
Marhoefer
[57] ABSTRACT
An enhanced input-output element has a self-timed interface (STI) in which a clock signal clocks bit serial data onto a parallel, electrically conductive bus and the clock signal is transmitted on a separate line of the bus. The received data on each line of the bus is individually phase aligned with the clock signal to provide a cost effective, modular, broadband, input/output element that can serve economically two channels and is modularly scalable to serve several hundred channels.
3 Claims, 5 Drawing Sheets
