component comp "Two input comparator with hysteresis";
pin in float in0 "Inverting input to the comparator";
pin in float in1 "Non-inverting input to the comparator";
pin out bit out "Normal output. True when \\fBin1\\fR > \\fBin0\\fR (see parameter \\fBhyst\\fR for details)";
pin out bit equal "Match output.  True when difference between \\fBin1\\fR and \\fBin0\\fR is less than \\fBhyst\\fR/2";

param rw float hyst=0.0 """Hysteresis of the comparator (default 0.0)

With zero hysteresis, the output is true when \\fBin1\\fR > \\fBin0\\fR.  With nonzero
hysteresis, the output switches on and off at two different values,
separated by distance \\fBhyst\\fR around the point where \\fBin1\\fR = \\fBin0\\fR.
Keep in mind that floating point calculations are never absolute
and it is wise to always set \\fBhyst\\fR if you intend to use equal """;

function _ fp "Update the comparator";
license "GPL";
;;
FUNCTION(_) {
    double tmp = in1 - in0;
    double halfhyst = 0.5 * hyst;

    if(tmp < -halfhyst) {
	out = 0;
	equal = 0;
    } else if(tmp > halfhyst){
	out = 1;
	equal = 0;
    } else {
	equal = 1;
    }
}