Stephen B Barrett

US Patent:

56897316, Nov 18, 1997

Filed:

Jun 7, 1995

Appl. No.:

8/475545

Inventors:

Roderick Michael P. West - Colchester VT
Hiroyuki Ando - Essex Junction VT
Stephen B. Barrett - Williston VT
Peter Casavant - Williston VT
Edward K. Evans - Essex Junction VT
Daniel Liguori - Essex Junction VT
David Litten - Jericho VT

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1300

US Classification:

395882

Abstract:

A programmable serializer comprising a multi-bit input port, a multi-bit output port, at least one multiplexer and at least one programmable address counter corresponding to the multiplexer for generating a sequence of multiplexer data input addresses that are inputted into the multiplexer address input. The multiplexer has an output connected to the multi-bit output port, an address input and a plurality of data input channels having addresses. Each data input channel is connected to a corresponding bit of the multi-bit input port. At least one data input channel is coupled to the multiplexer output when the corresponding address of the data input channel is applied to the address input. The programmable address counter receives and stores an initial address value, an address increment value and a count value and generates a sequence of addresses based on these values. The initial address value represents the multiplexer data channel that is to be initially coupled to the multiplexer output.

US Patent:

52435997, Sep 7, 1993

Filed:

Jun 5, 1991

Appl. No.:

7/710623

Inventors:

Stephen B. Barrett - Williston VT
Clarence R. Ogilvie - Huntington VT

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H04J 304
H03K 1756

US Classification:

370112

Abstract:

N stage tree-type mutliplexers having multiple selects and associated processes for configuring the same are disclosed. The basic multiplexer has control signals which are disbursed throughout the tree for high performance multiplexing. Control signals are distributed such that different signals control at least one stage of the N stage tree and such that the signals controlling the selectors in each of the plurality of selector paths from the input stage to the output stage of the tree are unique. As an enhancement, circuitry for buffering the control signals provided to the input stage of the tree can be used to further reduce the capacitive load thereon.

US Patent:

49455095, Jul 31, 1990

Filed:

Mar 14, 1988

Appl. No.:

7/168031

Inventors:

Stephen B. Barrett - Williston VT
John Bula - Essex Junction VT
Alvar A. Dean - Colchester VT

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 700

US Classification:

364900

Abstract:

A mask generator for generating a mask having logical signals of a given level between positions indicated by beginning and ending addresses. Two decoders select respective binary signal lines indicating the starting and ending positions. The mask generator is composed of two mask generators operating on the higher and lower order binary signal lines respectively and which ripple from the ends of the mask towards the middle. Preferably, each of the dual mask generators has look-ahead carry capability.