Patent ID: 9671820
Date: 2017-06-06
CPC Classifications: G06F,H04L

Claim:
1. A communication device operating in a slave mode that receives a command transmitted from a communication device operating as a master device, by use of a synchronous serial communication bus including a clock signal line for transmitting a clock signal and a data signal line for transmitting data, analyzes the command, and returns a result of the analysis to the master device by use of the bus, the communication device operating in the slave mode comprising: a timer that starts when the master device starts communication with the communication device operating in the slave mode; a timer threshold value storage unit that stores a predetermined threshold value; a clock control unit that receives the clock signal from the master device through the clock signal line, and performs control for stopping the clock signal from being sent from the master device; a data control unit that transmits data to and receives data from the master device through the data signal line; a transmission temporary storage unit that temporarily saves the data transmitted by the data control unit; a command analysis unit that analyzes the command transmitted from the master device; and a control unit; wherein the control unit when requested from the master device to return a result of the analysis in the command analysis unit, controls the clock control unit to make the master device stop the clock signal while the command analysis unit analyzes the command, compares a value of the timer with the threshold value stored in the timer threshold value storage unit, if a result of the comparison is that the value of the timer is equal to or less than the threshold value, saves transmit data in the transmission temporary storage unit, cancels the control by the clock control unit for stopping the clock signal, and has the data control unit transmit the data saved in the transmission temporary storage unit to the master device in synchronization with the clock signal received by the clock control unit, and if the result of the comparison is that the value of the timer exceeds the threshold value, cancels the control by the clock control unit for stopping the clock signal, places the clock control unit in a state to receive the clock signal, and places the data control unit in a state to receive a slave address indicating a communication device operating in the slave mode.