Fail-safe option select sensing method

摘要

A method and apparatus for providing an option select signal to a microcontroller programmed to provide any of a plurality of control modes depending on which of a plurality of unique option select signals is detected on an option select pin. The option select signal is a composite of a default signal and an option signal which, if present, overrides the default signal. The microcontroller determines the control mode by comparing the signal on the option select pin with a reference signal which may be supplied to a reference signal pin or generated internally. IMAGE