US 4,254,475 AGranted

Microprocessor having dual frequency clock

AssigneeRaytheon Company

InventorsJoseph J. Cooney, A. Joel Mannion

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Abstract

A microcomputer having a microprocessor operative in response to a dual frequency clock, such microprocessor being adapted to read data stored in a programmable memory in response to address and read enable signals supplied to a programmable memory and being adapted to process such data in response to the clock pulses supplied by the dual frequency clock. The dual frequency clock produces clock pulses at a relatively low rate until such time as either a sensing device is activated or a time duration has passed, in which case the mine is to selfdestruct. When the sensor is activated the microprocessor commands the dual frequency clock to produce relatively high frequency clock pulses to enable the microprocessor to rapidly determine whether the mine should or should not be detonated. Relatively low power is consumed by the microcomputer during the period of time the processor is "counting time" and computing whether the predetermined period of time has arrived, i.e., whether the time for "self destruction" has arrived. When the sensor detects a potential enemy object, relatively rapid computation occurs in response to the relatively high frequency clock pulses to determine whether the mine should be detonated.

Claims3

Dependent claims

A microcomputer adapted to activate a mine in response to detection of a proper object or after a predetermined time period in the absence of the detection of a proper object during such predetermined time period, comprising:

(a) clock means adapted to produce clock pulses having one of a pair of different frequencies selectively in accordance with a control signal;
(b) sensor means adapted to produce a detection signal in response to a detected object;
(c) a program memory adapted to store a set of instructions representing the predetermined time and criteria for determining whether a detected object is the proper object;
and
(d) a microprocessor for executing the set of stored instructions in response to the clock pulses fed thereto by the clock means to determine whether the predetermined time has arrived, and, in response to the detection signal, whether the detected object is a proper object, such microprocessor producing the control signal for the clock means to enable such clock means to produce:
(i) clock pulses having a relatively low frequency when the microprocessor is determining whether the predetermined time period has arrived, enabling such microprocessor to execute such instructions at a relatively low rate;
or (ii), clock pulses at a relatively high frequency when the microprocessor is determining whether the detected object is a proper object, enabling the microprocessor to execute such instructions at a relatively higher rate.

4 more elements

Dependencies are inferred from the claim text.