Controller arrangement

1 . A control circuit, comprising:

a single input terminal for receiving digital control signals and analog control signals;

said digital signals being in a first digital state when below a first level, and being in a second digital state when above a second level;

said analog signals being within a range that is greater than said first level and less than said second level;

a comparator circuit coupled to said single input terminal for providing a first output when the level at said single input terminal is below said first level or when the level at said single input terminal is above said second level; said comparator circuit providing a second output when the level at said single input terminal is between said first level and said second level;

whereby said first output indicates that a signal at said single input terminal is a digital signal and said second output indicates that a signal at said single input terminal is an analog signal.

2 . A control circuit in accordance with claim 1 , wherein:

said comparator circuit comprises:

a first comparator operable to determine if said level at said single input terminal is below said first level; and

a second comparator operable to determine if said level at said single input terminal is above said second level.

3 . A circuit in accordance with claim 2 , comprising:

a logic element coupled to said first comparator and to said second comparator to provide an output indicative of whether said signal at said single input terminal is a digital signal or an analog signal.

4 . A method of operating a control circuit, comprising:

receiving, at a single input terminal, signals that may be digital signals and analog control signals;

determining whether the level of a signal at said single input terminal is below a first level;

determining whether said level of said signal at said single input terminal is above said second level;

providing a first output if said level is below said first level or if said level is above said second level; and

providing a second output if said level is between said first level and said second level;

whereby said first output indicates that a signal at said single input terminal is a digital signal and said second output indicates that a signal at said single input terminal is an analog signal.

5 . A method in accordance with claim 4 , comprising:

providing a first comparator operable to determine if said level at said single input terminal is below said first level; and

providing a second comparator operable to determine if said level at said single input terminal is above said second level.

6 . A method in accordance with claim 5 , comprising:

combining the outputs of said first and second comparators to provide an output indicative of whether said signal at said single input terminal is a digital signal or an analog signal.