Memory control device, memory device and image forming apparatus

A memory device, comprising:

• a memory;
• an interface part configured by a memory control signal wire;
• a memory control device configured on a chip, and connected to the memory through the memory control signal wire of the interface part;
• and
• a pull-up resistor connected to the memory control signal wire, and that pull up the memory control signal wire, wherein
• the memory control device comprises
• a memory control part that controls the memory through the interface part in accordance with a predetermined communication regulation;
• a first buffer that has an open-drain output, and configured to connect to the memory control part through a first signal wire and configured to connect to the memory through the memory control signal wire of the interface part;
• an illegal access detection part configured to connect a second signal wire connected to the memory control signal wire, and that detects an illegal access to the memory according to an access state from the memory control part to the memory and a signal state of the interface part, the illegal access detection part being connected to the memory control part through the first signal wire;
• and
• a signal control part that switches the signal state of the interface part from a write-allowed state, in which the interface part is able to be written, to a write-inhibited state, in which the interface part is protected from being rewritten, when the illegal access is detected by the illegal access detection part.