Patent ID: 7184501

Claim:
A system for synchronous serial communication which comprises a serial data transmitting component comprising: a storage means to store data fed by an external device; a clock that produces a clock signal having clock signal level transitions; a decision means to calculate a number of clock signal level transitions required for the transmission of said data for each of a number of transmission modes, and to decide which mode will allow the serial transmission of said data to occur in the least number of clock signal level transitions; and an output means to choose the mode which has been decided by the decision means as allowing the serial transmission of said data to occur in the least number of clock signal level transitions, to read said data stored in the storage means, and to transmit said data through the communication mode thus chosen, wherein there are available a first mode, which is a serial communication under which data are transmitted without being divided into blocks, and a second mode under which data to be transmitted are divided into blocks, firstly transmitted is block information notifying the block(s) to be transmitted, and secondly transmitted are the data included in the block(s) notified by the block information, and, on the data included in the block(s) not notified, the corresponding previous data stored in a data receiving component are used; and time required for a data transmission based on the first mode, and time required for the data transmission based on the second mode are calculated, and compared, and transmission of the data is achieved through the mode that is found have less time for transmission of the data.