| 摘要 |
PURPOSE:To directly convert data in a discontinuous area and to transfer it to a continuous area in the data transfer of direct memory access system of bit unit by providing a reading means, a converting means and a writing means. CONSTITUTION:In a case where the destination of transfer is a data compressing/extending circuit 101 as a data converting circuit, when an ROP section 103 cuts out an arbitrary area on a memory 102 and the data are directly transferred to the circuit 101, the circuit 101 compresses or extends the input data and outputs the data. For instance, when an arbitrary rectangular frame 112 on a CRT 111 is designated and processed, by making a segmenting process and compressing process continuously in one step, processing time can be shortened, and the used quantity of memory can be reduced. The same process is executed when compressed and sent data are extended and restored. Thus, data in a discontinuous memory area can be transferred directly to a continuous area. |
