Patent ID: 7460127

Claim:
A display control circuit incorporating a random access memory in which a display data is stored, comprising: an oscillation circuit which oscillates a reference clock to define a transfer period in which the display data is transferred from the random access memory to a display; a counter circuit which counts the number of the reference clocks; wherein the transfer period is determined by the number of counts of the reference clocks by the counter circuit; wherein the oscillation circuit comprises: a first oscillation circuit which starts an oscillation when a transfer request of the display data from the random access memory to the display is generated while the oscillation is stopped, and stops the oscillation when an access request to the random access memory is generated from the CPU or when the counter circuit counts a predetermined number of the reference clocks during the oscillation; a second oscillation circuit which starts an oscillation when the access request is stopped while the oscillation is stopped, and stops the oscillation when the counter circuit counts a predetermined number of the reference clocks during the oscillation; and the reference clock is generated by being oscillated by either one of the first oscillation circuit or the second oscillation circuit.