| 摘要 |
PURPOSE:To compress and extend image data at high speed by dividing the data into plural numbers and processing the divided data in parallel in plural compression or extension blocks. CONSTITUTION:A page memory iMEM stores the image data inputted from a picture input and output part 3 therein, and a four channel DMAC (DMA controller) uses respective channels in a compression and extension circuits 1, 2. In the compression control, the A point address of the iMEM is set to a channel zero in order to transfer the first half of the data of the iMEM to the compression and extension circuit 1 and an X point address of a CMEM is set to a channel 1 in order to transfer the compressed data to the memory CMEM. Similarly, in order to compress and transfer the last half of the data of the IMEM, it is set to channels 2, 3 for compressing and extending. A start command is issued to the compression and extension circuits 1, 2, a compression operation is carried out in parallel, and the compressed image data is transmitted to a display device or the like from the input and output part 3. |
