Patent attributes
Data is written to one of two frame buffers in write access cycles having write and non-write sub-periods. Data is read out to a display device from the other of the two frame buffers in read access cycles having read and non-read sub-periods. The writing of data and the reading of data are switched to a respective opposite frame buffer during a switching opportunity, a switching opportunity occurring when a read access cycle is in a non-read sub-period and a write access cycle is in a non-write sub-period. A count of the number of times a switching opportunity is not executed because a read access cycle is in a non-read sub-period while a write access cycle is in a write sub-period is incremented. If the count exceeds a particular threshold, a write access cycle subsequent to the count exceeding the threshold is masked. When a write access cycle is a masked data is not written into a buffer.