Image forming apparatus and methods to avoid read disturb errors by prohibiting a deep sleep state of the image apparatus until a recovery process has implemented when a read count of a program in a non-volatile memory reaches a threshold

1. An image forming apparatus comprising:

a communication interface configured to receive data;

a buffer configured to store the data received by the communication interface;

a main system configured to process the data stored in the buffer;

a subsystem configured to be controlled by the main system to perform a function of the image forming apparatus;

a system control unit configured to switch an operation status mode of the image forming apparatus between a normal status mode in which the main system and the subsystem are turned on, a deep sleep status mode in which the main system and the subsystem are turned off, and a light sleep status mode in which the main system is turned on and the subsystem is turned off; and

a data processing unit configured to, when the operation status mode is the deep sleep status mode, process the data received from the buffer if the data is determined to be processable by the data processing unit, and cause the system control unit to switch the operation status mode from the deep sleep status mode to the normal status mode if the data received from the buffer is determined not to be processable by the data processing unit,

wherein the main system includes a non-volatile memory that stores a controller program, and is configured to cause the system control unit to switch the operation status mode from the deep sleep status mode to the light sleep status mode according to the controller program if a read count of the controller program from the non-volatile memory reaches a threshold value,

wherein, if the read count reaches the threshold value, the main system is configured to cause the system control unit to inhibit switching of the operation status mode to the deep sleep status mode until the image forming apparatus next starts, cause the system control unit to switch the operation status mode from the deep sleep status mode to the light sleep status mode, and perform a recovery process of a storage area of the controller program in the non-volatile memory when the image forming apparatus next starts, and

wherein the threshold value is an upper limit of the read count at which a read disturb error does not occur in the non-volatile memory.

2. The image forming apparatus according to claim 1 , further comprising:

a cache memory,

wherein the data processing unit is configured to store status data of the image forming apparatus in the cache memory when the system control unit switches the operation status mode from the normal status mode to the deep sleep status mode, and determine that the data is processable by the data processing unit if the data received from the buffer is processable on the basis of the status data.

3. The image forming apparatus according to claim 1 ,

wherein the data that is determined to be processable by the data processing unit includes at least one of an Address Resolution Protocol (ARP) request, a Post Office Protocol version 3 (POP3) response, and a command to request the status of the image forming apparatus.

4. The image forming apparatus according to claim 1 ,

wherein the data processing unit is configured to determine that the data received from the buffer is not processable by the data processing unit if operation of at least one of the main system and the subsystem and/or acquisition of status information from at least one of the main system and the subsystem are necessary for processing the received data.

5. The image forming apparatus according to claim 1 ,

wherein the data determined not to be processable by the data processing unit includes at least one of print data, commands to read and/or write data stored in the subsystem, and a processing command for the subsystem.

6. The image forming apparatus according to claim 1 ,

wherein the data processing unit is configured to decrease speed at which data is stored into the buffer from the communication interface when the system control unit switches the operation status mode from the deep sleep status mode to the normal status mode, and return the speed to original speed when switching of the operation status mode is completed.

7. The image forming apparatus according to claim 1 ,

wherein the communication interface, the buffer, the system control unit, and the data processing unit are installed in a third hardware separated from a first hardware in which the main system is installed and a second hardware in which the subsystem is installed, and

wherein the system control unit does not turn off the third hardware and turns off the first hardware and the second hardware when the operation status mode is switched from the normal status mode to the deep sleep status mode, and turns on the first hardware and the second hardware when the operation status mode is switched from the deep sleep status mode to the normal status mode.

8. An image forming method comprising:

via a communication interface, receiving data;

via a buffer, storing the data received by the communication interface;

via a main system, processing the data stored in the buffer;

via a subsystem, performing a function of an image forming apparatus by being controlled by the main system;

via a system control unit, switching an operation status mode of the image forming apparatus between a normal status mode in which the main system and the subsystem are turned on, a deep sleep status mode in which the main system and the subsystem are turned off, and a light sleep status mode in which the main system is turned on and the subsystem is turned off;

via a data processing unit, when the operation status mode is the deep sleep status mode, processing data received from the buffer if the data is determined to be processable by the data processing unit, and causing the system control unit to switch the operation status mode from the deep sleep status mode to the normal status mode if the data received from the buffer is determined not to be processable by the data processing unit;

via the main system, causing the system control unit to switch the operation status mode from the deep sleep status mode to the light sleep status mode according to a controller program stored in a non-volatile memory of the main system if a read count of the controller program from the non-volatile memory reaches a threshold value; and

via the main system, if the read count reaches the threshold value, causing the system control unit to inhibit switching of the operation status mode to the deep sleep status mode before the image forming apparatus next starts, causing the system control unit to switch the operation status mode from the deep sleep status mode to the light sleep status mode, and performing a recovery process of a storage area of the controller program in the non-volatile memory when the image forming apparatus next starts;

wherein the threshold value is an upper limit of the read count at which a read disturb error does not occur in the non-volatile memory.

9. The image forming method according to claim 8 , further comprising:

decreasing a speed at which data is stored into the buffer from the communication interface when the system control unit switches the operation status mode from the deep sleep status mode to the normal status mode, and

returning the speed to original speed when switching of the operation status mode is completed.

10. An image forming apparatus comprising:

a communication interface configured to receive data;

a buffer configured to store the data received by the communication interface;

a main system configured to process the data stored in the buffer;

a subsystem configured to be controlled by the main system to perform a function of the image forming apparatus;

a system control unit configured to switch an operation status mode of the image forming apparatus between a normal status mode in which the main system and the subsystem are turned on, a deep sleep status mode in which the main system and the subsystem are turned off, and a light sleep status mode in which the main system is turned on and the subsystem is turned off; and

a data processing unit configured to, when the operation status mode is the deep sleep status mode, process the data received from the buffer if the data is determined to be processable by the data processing unit, and cause the system control unit to switch the operation status mode from the deep sleep status mode to the normal status mode if the data received from the buffer is determined not to be processable by the data processing unit,

wherein the main system includes a non-volatile memory that stores a controller program, and is configured to perform a recovery process of a storage area of the controller program in the non-volatile memory before causing the system control unit to switch the operation status mode to the deep sleep status mode according to the controller program if a read count of the controller program is from the non-volatile memory reaches a threshold value,

wherein the main system is configured to perform the recovery process before the operation status mode is switched to the deep sleep status mode if the operation status mode is switched to the deep sleep status mode before the image forming apparatus next starts, and perform the recovery process when the image forming apparatus next starts if the operation status mode is not switched to the deep sleep status mode before the image forming apparatus next starts,

wherein the threshold value is an upper limit of the read count at which a read disturb error does not occur in the non-volatile memory.

11. An image forming method comprising:

via a communication interface, receiving data;

via a buffer, storing the data received by the communication interface;

via a main system, processing the data stored in the buffer;

via a subsystem, performing a function of an image forming apparatus by being controlled by the main system;

via a system control unit, switching an operation status mode of the image forming apparatus between a normal status mode in which the main system and the subsystem are turned on, a deep sleep status mode in which the main system and the subsystem are turned off, and a light sleep status mode in which the main system is turned on and the subsystem is turned off;

via a data processing unit, when the operation status mode is the deep sleep status mode, process the data received from the buffer if the data is determined to be processable by the data processing unit, and cause the system control unit to switch the operation status mode from the deep sleep status mode to the normal status mode if the data received from the buffer is determined not to be processable by the data processing unit;

via the main system, performing a recovery process of a storage area of a controller program stored in a non-volatile memory of the main system before causing the system control unit to switch the operation status mode to the deep sleep status mode according to the controller program if a read count of the controller program from the non-volatile memory reaches a threshold value, and

via the main system, performing the recovery process before the operation status mode is switched to the deep sleep status mode if the operation status mode is switched to the deep sleep status mode before the image forming apparatus next starts, and performing the recovery process when the image forming apparatus next starts if the operation status mode is not switched to the deep sleep status mode before the image forming apparatus next starts,

wherein the threshold value is an upper limit of the read count at which a read disturb error does not occur in the non-volatile memory.