Image forming apparatus capable of receiving data in high speed in accordance with high speed data transmission interface

摘要

An image forming apparatus capable of receiving data in high speed in accordance with high speed data transmission interface. The invention includes, a DMA transmission device, a bi-directional communication device, a flag indicator for indicating a status of the receiving parallel data from a host system according to DMA transmission is executed or not by the DMA transmission device a control device controls executing of the bi-directional communication by the bi- directional communication device that when the flag indicator indicates the receiving parallel data from a host system according to DMA transmission is executed, a signal of availability of bi-directional communication is sent to the host system after the receiving parallel data from a host system according to DMA transmission is suspended. When said flag means indicates said receiving parallel data from the host system according to DMA transmission is not executed, a signal of availability of bi- directional communication is sent to the host system immediately.