Serial communication method and apparatus

The invention discloses a method of serial communication, wherein, master equipment is connected with a plurality of slave equipments; the master equipment provides a communication clock signal (CLK) to the slave equipment by a clock signal wire, notifies the slave equipment to start reading/writing operation by a synchronous signal (SYN), and transmits a slave equipment address or a register address to the slave equipment by a downstream data signal (CMD); and the master equipment transmits downstream data to the slave equipment by the downstream data signal (CMD), or the slave equipmen transmits upstream data to the master equipment by an upstream data signal (DAT). The method of serial communication comprises a serial communication method of the master equipment, a serial communication method of the slave equipment and a serial communication method for interaction of the master equipment and the slave equipment. The invention also discloses the master equipment and the slave equipment. The proposal of the invention has the advantages of easy realization, pin resource conservation and cost reduction.