Westinghouse Electric Corporation

Joel E Lawhon

Thomas J Neufelder

Robert F Eyler

Leigh G Miller

William J Martini

The invention comprises an interface for switching control of a memory management unit (MMU) between a central processing unit (CPU) having a register stack for storing data, and one or more coprocessors (COP) each having register stacks for storing data. The COP is operative when actuated to perform selected functions, not normally performed by the CPU, utilizing information in memory.

Microcoprocessor, memory management unit interface to support one or

An improved addressing circuit for memory system using a plurality of integrated circuit memory arrays is disclosed. Typical integrated digital memory arrays include an address input which accepts a digital signal which identifies the storage locations in the array and an array enable input signal. In typical arrays, the time to respond to the address input signals and the array input signal is different with decoding of the array enable signal typically being considerably faster than decoding of the address signal. In the disclosed addressing scheme, the arrays comprising the system are arranged such that a first portion of the system address signal is decoded to select the array with the remainder of the address portion serving to select the storage location within the selected array. The addressing is arranged such that for a sequentially addressed data block, a word is read from each of the arrays before the address inputs to the arrays is changed. This causes the memory access time to be considerably improved because the array input enable signals are normally decoded much faster than the address inputs.

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Catonsville, MD, United States of America

Joel E Lawhon