Motor control apparatus

A motor control apparatus comprising

• a motor as a drive source of a vehicle-mounted apparatus;
• a by-wire control circuit provided as a first control circuit for sequentially switching an energized phase of the motor to drive rotation of the motor;
• a second control circuit for transmitting a drive permission code to the by-wire control circuit when driving of the rotation of the motor is permitted, wherein the by-wire control circuit and the second control circuit are different circuits,
• wherein:
• the by-wire control circuit pre-stores
• a first table defining an energized phase address corresponding to each address and
• a second table defining an energized phase corresponding to each energized phase address;
• and
• when receiving the drive permission code, the by-wire control circuit switches the energized phase in a correct order of driving the rotation of the motor, by:
• calculating an address for access to the first table based on the drive permission code;
• calculating an energized phase address corresponding to the address by referring to the first table, thereby to calculate the energized phase address for access to the second table in the correct order;
• and
• determining the energized phase corresponding to the energized phase address by referring to the second table;
• and
• the second table is arrayed so that the energized phases are arranged in a failsafe usage order, which is different from the correct order of driving the rotation of the motor.