International Business Machines Corporation

Stephen B Barrett

Clarence Rosser Ogilvie

Alvar Antonio Dean

Roderick Michael West

Edward Kelley Evans

John Bula

David D Litten

Daniel Joseph Liguori

Peter Casavant

Hiroyuki Ando

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. The address increment value represents the increment that must be added to a current address in order to reach a next address. The count value represents the number of address that must be generated by the counter prior to restarting the sequence at the initial address value.

Programmable serializer using multiplexer and programmable address

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.

Tree-type multiplexers and methods for configuring the same

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.

Dual look ahead mask generator

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Williston, VT, United States of America

Stephen B Barrett