Method and apparatus for protecting an electronic system from erroneous operation due to static electricity

An electronic system, comprising:

• a control section including a microprocessor, a memory, and a programmable input/output interface, the control section for controlling operation of the electronic system;
• a visual display unit electrically connected to the control section, via said programmable input/output interface;
• a key input unit comprising a plurality of discrete keys including a timer setting function key that are independently operable by manual depression to provide to said microprocessor a plurality of unique input signals representing a plurality of different control functions, said key input unit being electrically connected to the control section, via said programmable input/output interface, for permitting a user to control operation of the electronic system;
• and
• wherein said control section protects said microprocessor from erroneous operation due to static electricity emanating from at least one of the key input unit and the visual display unit, via said programmable input/output interface, by the steps of:
• determining whether the timer setting function key is input from the key input unit;
• when the timer setting function key is input from the key input unit, setting an internal timer at a predetermined value and storing a set timer value in said memory, said set timer value for resetting a program state of said programmable input/output interface;
• storing a program state of said programmable input/output interface in said memory;
• driving the internal timer until a value ofthe internal timer reaches the set timer value stored in said memory;
• and
• reading the program state of said programmable input/output interface stored in said memory and resetting a present program state of said programmable input/output interface to the program state of said programmable input/output interface stored in said memory when the value of the internal timer driven reaches the set timer value stored in said memory.

A method for protecting an electronic system from erroneous operation due to static electricity said method comprising the steps of:

• providing a microprocessor and a memory for said electronic system;
• providing a key input unit and a visual display unit for said electronic system;
• providing a programmable input/output interface for said microprocessor and said memory of said electronic system, said programmable input/output interface being connected to said visual display unit and to said key input unit;
• determining whether a timer setting function key is input from the key input unit;
• when the timer setting function key is input from the key input unit, setting an internal timer at a predetermined value and storing a set timer value in said memory, said set timer value for resetting a program state of said programmable input/output interface;
• storing a program state of said programmable input/output interface in said memory;
• driving the internal timer until a value of the internal timer reaches the set timer value stored in said memory;
• and
• reading the program state of said programmable input/output interface stored in said memory and resetting a present program state of said programmable input/output interface to the program state of said programmable input/output interface stored in said memory when the value of the internal timer driven reaches the set timer value stored in said memory to thereby protect said electronic system from erroneous operation due to static electricity.