CRUM unit mountable in consumable unit of image forming apparatus and image forming apparatus using the same

A customer replacement unit monitor (CRUM), comprising:

• a memory to store data related with a consumable unit;
• a controller to,
• perform a comparison of a first clock signal received from an image forming apparatus to a predetermined time,
• convert through a decoding the first clock signal into a second clock signal based on the comparison of the first clock signal to the predetermined time, and
• manage the memory based on the converted second clock signal;
• and
• a power extracting circuit to extract power from the first clock signal during an idle section having different pulse widths than a data section,
• wherein the first clock signal is divided into the data section and the idle section having different pulse widths, and
• wherein the controller according to the decoding processes a data signal received from the image forming apparatus in synchronization with a data section of the second clock signal corresponding to the data section of the first clock signal.

An apparatus, comprising:

• a consumable apparatus to be involved in an image forming job;
• and
• a Customer Replacement Unit Monitor (CRUM) circuitry to store data related with the consumable apparatus and to receive a first clock signal from an image forming apparatus;
• wherein the first clock signal is divided into a data section and an idle section having different pulse widths, and
• wherein the CRUM circuitry performs a comparison of the first clock signal to a predetermined time, converts according to a decoding the first clock signal into a second clock signal based on the comparison of the first clock signal to the predetermined time, the second clock signal being a clock signal maintaining a high value or a low value in the idle section, extracts power from the first clock signal during the idle section, and processes a data signal received from the image forming apparatus using the second clock signal.