DMA CONTROL CIRCUIT AND METHOD FOR RECEIVING SIZE DATA OF DMA CHANNEL

摘要

PROBLEM TO BE SOLVED: To make it possible to transfer data of various sizes by a single direct memory access (DMA)channel. SOLUTION: Size data are received by a DMA request. When 1st size data are received, the data of 1st quantity (e.g. one word) are transferred through the control of a DMA controller 103 for the DMA request. When 2nd size data are received, the data of 2nd size (e.g. two words) are transferred through the controller 103. When the DMA processing can not be processed, the DMA request is stored in the controller 103. The transfer size can be judged when the stored DMA request is processed. When the size data are used, the data transfer of various sizes can be processed by the single DMA channel. The size data are used for increasing a DMA current address register by proper quantity after transferring data related to the size data through the DMA controller 103.