Apparatus controlled by a microprocessor
AssigneeTokyo Shibaura Denki Kabushiki Kaisha
InventorsToshio Kakizawa, Itsuo Sakai
Life of this patent
Estimating the term…
Abstract
A control circuit using a microprocessor comprises a time counting circuit; a main control logic circuit receiving a time signal from the time counting circuit; and an AC signal generator receiving a first signal from the time counting circuit and a second signal from the main control logic circuit. When the microprocessor is out of order, the AC signal takes continuous "1" or "0" level. The control circuit further comprises a detecting circuit for detecting an abnormal state of the AC signal and a control circuit for maintaining an apparatus to be controlled by the control circuit in a predetermined safe state when the detecting circuit detects the abnormal state of the AC signal.
Claims7
An apparatus controlled by a microprocessor comprising:
- an integrated microprocessor including:
- a time counting logic means supplied with a reference input signal for counting said input signal and producing a first signal,
- a main control logic means receiving said first signal for producing a second signal and at least one output signal for controlling said apparatus, and
- an AC signal generating logic means receiving said first and second signals for producing an AC signal and a third signal, said AC signal being produced at a first operation state of said microprocessor and having a first and second levels repeated alternatively, said third signal being produced at a second operation state of said microprocessor and having one of said first and second levels for a predetermined time period;
- a detecting means for detecting said AC signal to produce a first detection signal and for detecting said third signal to produce a second detecting signal;
- and
- a protecting means connected to said detecting means and applying a fourth signal to said apparatus for putting said apparatus into a safety condition when said protecting means receives said first detection signal.
Dependencies are inferred from the claim text.