PURPOSE: To enable arbitrary split driving to be performed with one device, by changing split number setting signal for input to an address arithmetic cir cuit.

CONSTITUTION: From an address arithmetic circuit 11, address signal AD is outputted through advancing command pulse, rotational direction input signal, step number setting signal N, and split number setting signal M. The address signal AD is outputted to the first and the second memory units 12, 13 of a ROM. With the first memory unit 12 and a second D/A converter 14, a first exciting current value setting signal forming circuit 16 is formed. With the second memory unit 13 and a second D/A converter 15, a second exciting current value setting signal forming circuit 17 is formed. By a stepping motor driving unit 18, exciting current for exciting a stepping motor 2 with two sorts of exciting current value setting signals for input signals is formed.