Stepping motor control circuit

A stepping motor control circuit (50) for controlling a stepping motor according to stepping pulses sent from a host device (49), said control circuit comprising:

• a step circuit (51) for generating a control clock pulse based on said stepping pulse from said host device;
• a track circuit (52) composed of an up-down counter circuit (1) for counting said control clock pulse from said step circuit and a decoder circuit (2) for decoding the outputs from said counter circuit into excitation outputs, said track circuit being capable of setting a two-phase excitation system and a one-two phase excitation system or a two-one phase excitation system;
• and
• an offset circuit (11) for speeding up a changing of the carry value from a first digit to a second digit between a normal rotation and a reverse rotation of the stepping motor,
• whereby, when the two-phase excitation system is set, said excitation outputs start to change at the input timing of the first control clock pulse for the normal rotation and the reverse rotation of the stepping motor.