Image forming apparatus capable of processing data at high speed in accordance with a high speed data transmission interface

摘要

An image forming apparatus capable of processing data at a relatively high speed in accordance with a data transmission speed from a host system. The image forming apparatus includes a central processing unit, a memory, and a host system interface. When data inclusive of print data and control data is transmitted from the host system to the image forming apparatus, the host system interface starts a direct memory access (DMA) with the memory to store the print data at a relatively high speed in accordance with the data transmission speed from the host system. The host system interface includes a data receiver to be connected to the host system, a data determiner, a control data checker, a print data register, a control data register, a DMA address register, and an address counter. The data determiner determines whether received data is print data or control data by comparing control data stored in the control data checker, executes DMA operation when the received data is print data, while terminating DMA when the received data is control data.