A method for accessing a single port memory is provided. A single port memory is used as a line buffer and divided into a plurality of memory blocks. The line buffer data is written into or read out from these memory blocks by turns with a special sequence corresponding to the operation mode; for example, a normal mode or a PLM mode. Therefore, the line buffer data can be written into or read out from the line buffer at the same time, and the size and cost of integrated circuit can be reduced.