Magnetic-field detection microcomputer and magnetic-field detecting method

A magnetic-field detecting method performed by a magnetic-field detection microcomputer including:

• a magnetic-field detection device which detects a magnetic field;
• a differential amplifier which amplifies an output voltage from the magnetic-field detection device;
• a variable voltage circuit which generates, according to a voltage control signal, a reference voltage that is variable;
• a comparator which compares an output from the differential amplifier with the reference voltage generated by the variable voltage circuit;
• a voltage controlling register which holds a voltage control value for controlling a level of the reference voltage generated by the variable voltage circuit, and outputs the voltage control signal having the voltage control value to the variable voltage circuit;
• and
• a storage unit configured to previously store a first table in which a magnetic-field intensity indicating an intensity of the magnetic field to be applied to the magnetic-field detection device and the voltage control value are associated with each other,
• the magnetic-field detecting method comprising:
• setting, to the voltage controlling register, the voltage control value corresponding to the magnetic field to be detected;
• determining whether or not an output from the comparator is inverted;
• and
• reading out the magnetic-field intensity associated with the voltage control value from the first table, when in the determining, the output from the comparator is determined to be inverted.