Unit using OS and image forming apparatus using the same

1. A customer replaceable unit monitoring (CRUM) chip mountable in a replaceable unit that is mounted in a main body of an image forming apparatus, the CRUM chip comprising:

a memory unit storing an initialization program different from an operating system (O/S) operated in a main controller mounted in the main body, unique information associated with the replaceable unit, and status information on use of the replaceable unit; and

a central processing unit (CPU) coupled to the memory unit, wherein the CPU performs initialization of the replaceable unit using the initialization program and updates the status information stored in the memory unit based on information on use of consumables used in the image forming apparatus transmitted through a serial interface from the main body.

2. The CRUM chip as claimed in claim 1 , wherein the CPU receives a communication message where the information on use of the consumables is combined with a message authentication code (“MAC”) from the main body.

3. The CRUM chip as claimed in claim 2 , wherein the communication message includes a command to update the status information of the consumables stored in the memory unit.

4. The CRUM chip as claimed in claim 3 , wherein the information on use of the consumables and the command are encrypted using a predetermined encryption algorithm.

5. The CRUM chip as claimed in claim 4 , wherein the CPU decrypts the information on use of the consumables and the command encrypted using the encryption algorithm.

6. The CRUM chip as claimed in claim 2 , wherein the CPU receives encrypted information on use of the consumables using a predetermined encryption algorithm from the main body.

7. An image forming apparatus, comprising:

a main body having a main controller which controls an operation of the image forming apparatus;

a replaceable unit mounted in the main body to communicate with the main controller through a serial interface;

a customer replaceable unit monitoring (CRUM) chip mounted in the replaceable unit,

wherein the CRUM chip comprises:

a memory unit storing an initialization program different from an operating system (O/S) operated in a main controller mounted in the main body, unique information associated with the replaceable unit, and status information on use of the replaceable unit; and

a central processing unit (CPU) coupled to the memory unit,

wherein the main controller of the main body transmits information on use of consumables used in the image forming apparatus to the CRUM chip through the serial interface,

wherein the CPU of the CRUM chip performs initialization of the replaceable unit using the initialization program and updates the status information stored in the memory unit based on information on use of consumables transmitted from the main controller.

8. The apparatus as claimed in claim 7 , wherein the main controller transmits a communication message where the information on use of the consumables is combined with a message authentication code (MAC) to the CRUM chip.

9. The apparatus as claimed in claim 8 , wherein the communication message includes a command to update the status information of the consumables stored in the memory unit.

10. The apparatus as claimed in claim 9 , wherein the main controller encrypts the information on use of the consumables and the command using a predetermined encryption algorithm and transmits the encrypted information and command to the CRUM chip.

11. The apparatus as claimed in claim 10 , wherein the CRUM chip decrypts the information and command encrypted using the encryption algorithm.

12. The apparatus as claimed in claim 8 , wherein the main controller transmits the information on use of the consumables encrypted using the predetermined encryption algorithm to the CRUM chip.

13. The apparatus as claimed in claim 7 , wherein the replaceable unit is a toner cartridge.

14. An image forming apparatus, comprising:

a main body including a main controller to control an operation of the image forming apparatus;

a replaceable unit mounted on the main body to communicate with the main controller through a serial interface; and

a customer replaceable unit monitoring (“CRUM”) chip mounted in the replaceable unit,

wherein the CRUM chip comprises:

a memory unit storing unique information associated with the replaceable unit and status information on use of the replaceable unit; and

a central processing unit (“CPU”) which is communicable with the memory unit,

wherein the main controller of the main body transmits information on use of the consumables to the CPU through the serial interface,

wherein the CPU of the CRUM chip updates the status information stored in the memory unit based on information on use of the consumables used in the image forming apparatus transmitted from the main body.

15. The apparatus as claimed in claim 14 , wherein the main controller generates a communication message combining the information on use of the consumables with a MAC and transmits the communication message to the CRUM chip.

16. The apparatus as claimed in claim 15 , wherein the communication message includes a command to update the status information of the consumables stored in the memory unit.

17. The apparatus as claimed in claim 16 , wherein the main controller encrypts the information on use of the consumables and the command using a predetermined encryption algorithm and transmits the encrypted information and command to the CRUM chip.

18. The apparatus as claimed in claim 17 , wherein the CRUM chip decrypts the information on use of the consumables and the command encrypted using the encryption algorithm.

19. The apparatus as claimed in claim 18 , wherein the replaceable unit is a toner cartridge.