Crum chip, image forming apparratus, and communication method of crum chip

A communication method of a CRUM chip mountable on a consumables unit of an image forming apparatus, the method comprising:

• receiving a first signal including first data and first integrity monitoring data for the first data from a main body of the image forming apparatus;
• separating the first integrity monitoring data from the first signal and monitoring integrity of the first signal;
• temporarily storing the first data and the first integrity monitoring data included in the first signal when it is determined that the first signal is integrity data;
• generating second data to be transmitted to a main body of the image forming apparatus when the second data is present;
• generating second integrity monitoring data using the second data and the first integrity monitoring data;
• and
• transmitting a second signal including the second data and the second integrity monitoring data to the main body of the image forming apparatus.

A method of establishing communication between a CRUM chip mountable on a consumables unit and an image forming apparatus, the method comprising:

• initializing the CRUM chip separate from an initialization of the image forming apparatus;
• receiving a first signal including first data and first integrity monitoring data;
• generating second integrity monitoring data and verifying the integrity of the first signal;
• generating and transmitting a second signal including second data and the second integrity monitoring signal that includes the first integrity monitoring data;
• and
• verifying the integrity of the second signal to establish communication between the consumables unit and the image forming apparatus.