Patent ID: 6988153

Claim:
A data storing system comprising: a plurality of drive units for writing data transmitted via a bus on a storing media and reading data from a storing media and transmitting the data via the bus in parallel; and a transmission control device for controlling data transmission made by each of said plurality of drive units respectively, wherein the transmission control device includes: a bus control unit operable to give a bus use right responding to a request for a bus use right made by the respective drive units according to predetermined rules; a request threshold calculation unit operable to calculate a request threshold showing a timing at which the respective drive units request the bus use right based on the number of the drive units, a data transmission speed of the bus and either a data reading speed or a data writing speed of the respective drive units; and a request threshold notification unit operable to notify the respective drive units of the calculated request threshold, and the respective drive units include: a buffer for storing data transmitted between the storing medium and the bus temporally; a recording head for reading the data from the storing medium so as to store the data in the buffer and read the data from the buffer so as to write the data on the storing medium; and a control unit for requesting and acquiring the bus use right and transmit the data between the buffer and the bus when data amount in the buffer increases or decreases to the notified request threshold.