Apparatus for effecting high speed transfer of video data into a video memory using direct memory access

摘要

The present invention realizes high-speed transfer of video data into a video memory. Addresses used in DMA transfer operation are calculated by simple arithmetic operation in a DMA address operation unit of a DMA controller. Video data are transferred according to the addresses at a high speed to an arbitrary position in a VRAM. An FIFO memory unit can expand and reduce a video image by desirable magnifications in both vertical and horizontal directions during DMA transfer of video data.