05442769 is referenced by 12 patents and cites 31 patents.

A processor specially adapted for use as a coprocessor. The processor is implemented as a microprocessor. The adaptations include the following: The microprocessor has a master-slave pin which receives an input which determines whether the microprocessor operates as a bus master or a bus slave. Certain output pins have three-state bus drivers which employ feedback to ensure that a signal on a line being driven by the driver has gone inactive before the driver is turned off. Instructions executed by the microprocessor permit specification of portions of the internal registers as sources and destinations and specification of the size of an ALU operation, permitting easy operation on data ranging from bytes through 24-bit pointers. Instructions are executed in an instruction pipeline and a separate I/O instruction pipeline. Some pipeline stalls are avoided by means of a special MOVE instruction which differs from an ordinary MOVE instruction in that it does not cause pipeline stall when it reads data from a register loaded by a preceding READ instruction. The microprocessor also has an Intel/Motorola pin whose input specifies the type of host processor the coprocessor is working with and further executes UO instructions which permit the see code to be used with either host processor.

Title
Processor having general registers with subdivisions addressable in instructions by register number and subdivision type
Application Number
493021
Publication Number
5442769
Application Date
April 7, 1993
Publication Date
August 15, 1995
Inventor
Robert C Fairfield
Randolph
NJ, US
Gary T Corcoran
Fanwood
NJ, US
Agent
Gordon E Nelson
Assignee
AT&T
NJ, US
IPC
G06F 9/34
G06F 12/04
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