Honeywell G.m.b.h.

Burke B Baumann

William J Pantry

Robert L Spiesman

Troy K Wilson

The data processing system, has at least one memory unit operatively connected to a memory bus, and further has an input/output (I/O) bus controller for interfacing at least one peripheral device to the data processing system. The data processing system comprises a first bus which provides a first transmission medium between the peripheral device and the memory bus. A second bus, provides a second transmission medium between a CPU and the memory bus. A logic element, interposed between the first and second bus, and the memory bus, interfaces the first and second bus to the memory bus in response to request signals from the first and second bus.

Dual bus system

A controller of a microprocessor includes a control store for storing microinstructions. A programmable logic array (PLA), enabled when a predetermined macroinstruction type is to be executed, translated the operand field of the macroinstruction into information bits which are used to modify the microinstruction as it is being fetched from the control store. The bits of the microinstruction which are changeable are coupled from the control store to a first input of a multiplexer. The output of the PLA is coupled to a second input of the multiplexer. A select signal for the multiplexer is generated when the predetermined instruction type is to be excuted, thereby effecting a modification of the fetched microinstruction, and yielding a modification to the basic operation of the macroinstruction.

Apparatus for modifying microinstructions of a microprogrammed processor

A circuit for producing a receive Manchester clock from serially received Manchester encoded data signals. The encoded data signals are differentiated to produce a primary clock pulse for each voltage transition of the applied signals. Each primary clock pulse is delayed a predetermined period of time to produce secondary clock pulse and each secondary clock pulse is delayed for substantially the same period of time to produce a tertiary clock pulse. The primary, secondary and tertiary clock pulses are applied to a gate which produces a receive Manchester clock pulse when a primary, secondary, or tertiary clock pulse is applied to the gate. The frequency of the receive Manchester clock is twice that of the basic frequency of the received Manchester encoded data signals.

Receive Manchester clock circuit

An arbitration circuit comprises a plurality of enabling elements which determines when predetermined conditions exist to transmit a request signal. A first gate combines transmitted request signals to generate a combined request signal. A plurality of first latches, each first latch having a sequential priority order and operatively connected to a corresponding enabling element, and further connected to the output of the first gate, generates an enable and a disable signal. A plurality of second gates is included, each second gate is operatively connected to the first gate to receive the combined request signal, and each second gate operatively connected to the corresponding first latch to receive the enable signal. Further, each of the second gates is operatively connected to each first latch having a higher sequential priority to receive the disable signal from each of the higher sequential priority first latches, each of the second gates generating a select control signal corresponding to the request signal selected by the arbitration circuit, thereby permitting a requestor access to the bus.

Growing community of inventors

Glendale, AZ, United States of America

Burke B Baumann