Method and apparatus for communication using control bus

A method and a device for performing communication with a control bus are provided to require no additional process for transferring an instruction whenever the instruction is transferred through the control bus and prevent speed of whole digital device from getting slower by simply transferring the instruction without any processes for transferring the instruction. A baseband unit(300) transfers an instruction through a control bus, which is an I2C bus, and reads an execution result of the instruction. An I2C(Inter IC) device(310), which includes a processor(316) for performing action according to the received instruction, receives the instruction from the baseband unit and records the execution result of the instruction. The baseband unit transfers the instruction when an ACK(ACKnowledgement) signal is received from an I2C slave(312) included in the I2C device. The I2C slave outputs an NAK(Negative AcKnowledgement) signal to the baseband unit when the instruction is received. The I2C device makes the I2C slave output the ACK signal again and the baseband unit reads the corresponding data according to the ACK signal when the received instruction is a read instruction.