JP2006277363A - Information transfer system, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the processing rate in an information processor provided with an information transfer system for executing data transfer between a module and a memory based on descriptor information. <P>SOLUTION: A priority that is an index for adjusting the use right of a shared bus 22 by modules 1-4 (corresponding to a second priority) is included in descriptor information Z1-Z4 including sizes of data Y1-Y4 to be transferred between the modules 1-4 and a memory 30 or the like, and the use right of the shared bus 22 by a plurality of modules 1-4 is adjusted based on the priority according to the descriptor information Z1-Z4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an information transfer technique represented by DMA (Direct Memory Access) transfer and the like, and more particularly to an arbitration process for arbitrating bus use rights by a plurality of masters (modules).

  As shown in FIG. 7, data transfer between various modules 101 to 104 included in the input / output device and the memory 130 storing various data is directly performed via buses 121 and 122. In the system X3 that realizes DMA transfer, the central processing unit (CPU) that controls the system X3 in an integrated manner is not involved in the data transfer, so the processing load on the CPU is reduced and the processing speed of the entire system X3 is increased. Can be achieved. In order to execute this DMA transfer, the modules 101 to 104 first obtain descriptor information (transfer control information) stored in the descriptor storage area 131 of the memory 130, and then, based on the descriptor information, the memory 130. Write data to the data storage area 132 or read data from the data storage area 132 (data transfer). Here, each of the descriptor information includes, for example, “Source Address”, “Destination Address”, “Data Size” relating to data transferred between the modules 101 to 104 and the memory 130, as shown in FIG. “,“ Next Descriptor Address ”,“ Reserved ”,“ User bit ”× 3.

On the other hand, in the configuration such as the system X3 in which the memory 130 is shared by the modules 101 to 104, multiple accesses to the memory 130 by the modules 101 to 104 occur, and the bus band of the bus 122 is saturated. It is possible to do. Therefore, an arbitration device 108 that arbitrates the right to use the bus 122 by the modules 101 to 104 is provided (see, for example, Patent Documents 1 and 2). The arbitration by the arbitration device 108 is performed according to an arbitration method such as a fixed priority method or a round robin method. Here, in the fixed priority method, when multiple accesses from the modules 101 to 104 to the memory 130 occur, the bus 122 is used for the module having the highest priority preset for each of the modules 101 to 104. It is a technique for granting rights, and its priority is fixed. On the other hand, the round robin method is a method of changing the priority of the module that executed the process to the lowest and the priority of the other modules to one higher as the processes of the modules 101 to 104 progress.
JP-A-8-129524 JP 2001-184299 A

However, in the conventional bus arbitration method, the priority as an index when arbitrating the right to use the bus is determined depending on the module regardless of the data transferred between the module and the memory. The priority cannot be changed according to the size of data to be transferred. In general, the processing speed of an information processing apparatus typified by an image forming apparatus or a personal computer is strongly influenced by the data transfer speed in the information processing apparatus. Therefore, unless the data transfer between the plurality of modules and the memory is not performed efficiently, the processing speed of the information processing apparatus cannot be improved.
Accordingly, the present invention has been made in view of the above circumstances, and the object of the present invention is to provide a priority that serves as an index for arbitrating the right to use the bus to descriptor information including the size of data to be transferred. And an information transfer method capable of improving the processing speed of the information processing apparatus by arbitrating the right to use the bus by a plurality of modules based on the priority according to the descriptor information. It is in.

To achieve the above object, the present invention provides a storage means (memory) for storing a plurality of data and a plurality of descriptor information corresponding to each of the data, and the storage means based on the descriptor information acquired from the storage means. The priority of the use of the shared bus connecting the plurality of data transfer means (modules) for transferring data to and from the first priority information set in advance for each of the plurality of data transfer means The present invention is applied to an information transfer system including an arbitration unit that performs arbitration based on the use of the shared bus in which the data transfer unit arbitrates based on the first priority information by the arbitration unit. The descriptor information is acquired from the storage means according to the priority order of the data, and then the data is transferred to and from the storage means when the data is transferred. The arbitration unit is notified of second priority information set in advance for each descriptor information included in the scripter information, and the arbitration unit reports the second priority information notified by the data transfer unit. Constructed as an information transfer system characterized by arbitrating the priority of use of the shared bus by the plurality of data transfer means based on priority information, thereby including the size of data to be transferred, etc. Based on the second priority information included in the descriptor information, that is, the second priority information corresponding to the descriptor information, arbitration of the right to use the shared bus by the plurality of data transfer means is performed. Therefore, the data transfer between the plurality of data transfer means and the storage means is efficiently performed. It is possible to improve the processing speed of the physical device.

In addition, the arbitrating unit arbitrates the priority of use of the shared bus by the plurality of data transfer units based on the third priority information based on the second priority information notified by the data transfer unit. It is conceivable to be configured to do so.
For example, for the purpose of realizing arbitration of a priority order suitable for each operation mode of the information processing apparatus adopting the information transfer method, the arbitration unit sets priority corresponding to the operation mode in the information processing apparatus. A storage unit for storing information, determining a current operation mode in the information processing apparatus, and setting one priority among a plurality of priority setting information stored in the storage unit according to the determination result Information is selected, and the third priority information is set based on the selected priority setting information and the second priority information notified by the data transfer means. As a result, the priority of use of the shared bus by the plurality of data transfer means is arbitrated based on the third priority information set according to the operation mode of the information processing apparatus.
The present invention may also be understood as an image forming apparatus provided with the information transfer method described above. In this case, the type of the operation mode may be, for example, a print mode or a scanner mode.

According to the present invention, based on the second priority information included in the descriptor information including the size of data to be transferred, that is, based on the second priority information corresponding to the descriptor information, By performing arbitration of the right to use the shared bus by the data transfer means, data transfer between the plurality of data transfer means and the storage means is efficiently performed. The processing speed of the processing apparatus can be improved.
Further, the third priority information is set based on the second priority information and the current operation mode of the information processing apparatus, and the use of the shared bus is determined based on the third priority information. By arbitrating the priority order, it is possible to realize arbitration of a suitable priority order for each operation mode of the information processing apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
FIG. 1 is a block diagram showing a schematic configuration of a system X1 adopting the information transfer method according to the embodiment of the present invention, FIG. 2 is a diagram showing an example of descriptor information in the present invention, and FIG. 3 is an arbitration process. 10 is a flowchart for explaining an example of a procedure of an arbitration process executed by a unit 81.
First, a schematic configuration of a system X1 employing the information transfer method according to the embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 1, the system X1 is roughly configured to include a CPU (Central Processing Unit) 10, an ASIC (Application Specific Integrated Circuit) 20, and a memory 30 (an example of storage means). It is mounted on an image forming apparatus (an example of an information processing apparatus) (not shown) having a scanner function for reading a document image and a print function for executing print output of the document image. In this embodiment, an example of an information transfer method applied to the system X1 mounted on the image forming apparatus will be described. However, the system X1 is mounted on another information processing apparatus such as a personal computer. Examples are possible.

The ASIC 20 includes a plurality of modules 1 to 4 (an example of data transfer means) that execute DMA transfer with the memory 30 to achieve the functions in the image forming apparatus, and the modules 1 to 4 Shared buses 21 and 22 that establish a connection (channel) to the memory 30, an arbitration device 8 (an example of an arbitration unit) that arbitrates the priority of use of the shared bus 22 by the modules 1 to 4, and the arbitration device 8 and a BIU (Bus Interface Unit) 7 for relaying a connection between the CPU 10 and the CPU 10.
When the use request of the shared bus 22 by the modules 1 to 4 competes, the arbitrating device 8 gives the right to use the shared bus 22 to any module in order to resolve the conflict, and the use right is granted. An arbitration processing unit 81 that executes an arbitration process for waiting for use of the shared bus 22 by another module that does not have is provided.
The arbitration processing unit 81 includes a memory (not shown) that stores a first priority (corresponding to first priority information) preset for each of the modules 1 to 4. When the use requests of the shared bus 22 by .about.4 compete, the right to use the shared bus 22 is given to the module having the highest priority stored in the memory. In the present embodiment, it is assumed that the first priorities “1” to “4” corresponding to the modules 1 to 4 are set in advance.

The modules 1 to 4 perform DMA transfer with the memory 30, and according to the priority order of use of the shared bus arbitrated based on the first priority by the arbitration processing unit 81. When descriptor information Z1 to Z4 (to be described later) is acquired from the memory 30 and data is subsequently transferred to the memory 30 based on the descriptor information Z1 to Z4, the descriptor information is included in the descriptor information Z1 to Z4. The arbitration processing unit 81 is notified of a second priority to be described later.
The system X1 is different from the conventional system in that the modules 1 to 4 are configured to notify the arbitration processing unit 81 of the second priority as described above, and the arbitration processing unit 81 includes the modules 1 to 1. When the second priority is notified from 4, the bus contention of the modules 1 to 4 is arbitrated based on the second priority. This point will be described in detail in the arbitration process (S1 to S4) described later.

  The memory 30 stores a data storage area 32 for storing various data Y1 to Y4 and descriptor information Z1 to Z4 corresponding to the data Y1 to Y4 stored in the data storage area 32, respectively. This is a DDR-SDRAM (Double Data Rate SDRAM) having a descriptor storage area 31. In this embodiment, an SDRAM having a high-speed data transfer function called a double data rate (DDR) mode is used. However, the present invention is not limited to this.

Here, the data structure of the descriptor information Z1 to Z4 stored in the descriptor storage area 31 will be described with reference to FIG.
As shown in FIG. 2, each of the descriptor information Z1 to Z4 is data in units of 32 bytes (32 bits × 8), and “Source Address”, “Destination Address”, “Data Size”, “Next Descriptor” for every 32 bits. It consists of each information of “Address”, “Reserved”, “User bit” × 3. One data amount (32 bytes in this case) of the descriptor information Z1 to Z4 depends on the specifications of the memory 30 and the bus bandwidth of the buses 21 and 22 in order to achieve a high-speed data transfer function in the system X1. Set as appropriate.
In the “Reserved” data area of the descriptor information Z1 to Z4, “Priority” indicating a second priority serving as an index when the priority order of use of the shared bus 22 by the modules 1 to 4 is arbitrated. "Is included (the data area 31a shown (for example, about 4 bits)). As a result, when each of the modules 1 to 4 acquires the descriptor information Z1 to Z4 stored in the descriptor storage area 31, the second priority from the "Priority" included in the descriptor information Z1 to Z4. Will get the degree. In the present embodiment, it is assumed that the second priorities “4” to “1” corresponding to the descriptor information Z1 to Z4 are set in advance.

In the system X1 configured as described above, when the modules 1 to 4 acquire the descriptor information Z1 to Z4 from the memory 30 by the arbitration processing unit 81 of the arbitration device 8, the modules 1 to 4 are used. When the priority of use of the shared bus 22 is adjusted based on the first priority, the modules 1 to 4 perform data transfer with the memory 30 based on the descriptor information Z1 to Z4. The priority of the use of the shared bus 22 by the modules 1 to 4 is arbitrated based on the second priority.
Hereinafter, an example of the procedure of the arbitration process executed by the arbitration processing unit 81 in the system X1 will be described with reference to the flowchart of FIG. In the figure, S1, S2,... Represent processing procedure (step) numbers.

First, the arbitration for resolving the contention for the use of the shared bus 22 by the module 1 and the module 3 that occurs when the module 1 and the module 3 obtain the descriptor information Z1 and the descriptor information Z3 from the memory 30. Processing will be described.
It should be noted that the contention for the use request of the shared bus 22 by the module 1 and the module 3 is, for example, the use of the shared bus 22 by the module 1 and the module 3 while the module 2 is using the shared bus 22. Occurs when the use of the shared bus 22 by the module 2 ends after a request is made and the two use requests are waited.

First, in step S1, the arbitration processing unit 81 determines whether or not the use requests of the memory 30 by the modules 1 to 4 compete. Specifically, the determination is made based on whether or not the access request signal to the memory 30 and the use request signal for the shared bus 22 transmitted from the modules 1 to 4 are simultaneously received from a plurality of modules. Here, since it is determined that the use requests of the shared bus 22 by the module 1 and the module 3 are in conflict (Yes side of step S1), the process proceeds to step S2.
The determination in step S1 is continuously executed until it is determined that the use request for the shared bus 22 is in conflict, and it is determined that the use request for the shared bus 22 is not in conflict ( In step S1 (No side), the shared bus 22 is used by each of the modules 1 to 4 in the order in which the shared bus 22 is requested to be used.

  In the subsequent step S2, the arbitration processing unit 81 determines whether or not the second priority has been notified from the module 1 or the module 3 with which the use request of the shared bus 22 is competing. At this time, the module 1 and the module 3 have not yet acquired the descriptor information Z1 and the descriptor information Z3 stored in the memory 30. Therefore, since the second priority is not notified from the module 1 or the module 3 to the arbitration processing unit 81 (No side of step S2), the process proceeds to step S3.

In step S <b> 3, the arbitration processing unit 81 arbitrates the use priority of the shared bus 22 by the module 1 and the module 3 based on the first priority of the module 1 and the module 3. . As described above, the first priorities of the module 1 and the module 3 in the present embodiment are “1” and “3”, respectively. Accordingly, in the process of step S3, it is determined that the module 1 has a higher priority than the module 3, and the right to use the shared bus 22 is given to the module 1, and the shared bus by the module 3 is given. The use of 22 is awaited.
Thereafter, when the module 1 acquires the descriptor information Z1 corresponding to the module 1 from the memory 30 and releases the shared bus 22, the arbitration processing unit 81 grants the right to use the shared bus 22 to the module 3. The module 3 obtains the descriptor information Z3 corresponding to the module 3 from the memory 30.
As described above, the module 1 and the module 3 correspond to the memory 30 according to the priority of use of the shared bus 22 that is arbitrated by the arbitration processing unit 81 based on the first priority. The descriptor information Z1 and Z3 to be acquired are acquired. Here, as described above, each of the descriptor information Z1 to Z4 includes the preset second priorities “4” to “1” corresponding to the descriptor information Z1 to Z4. , The module 1 acquires the second priority “4” included in the descriptor information Z1, and the module 3 acquires the second priority “2” included in the descriptor information Z3. .

Subsequently, the module 1 and the module 3 exchange the descriptor information Z1 and the descriptor information Z3 with the memory 30 based on the descriptor information Z1 and the descriptor information Z3 acquired from the memory 30, respectively. Arbitration processing for resolving contention for use requests of the shared bus 22 by the module 1 and the module 3 that occur when data transfer of corresponding data Y1 and data Y3 is started will be described.
Here, since each of the module 1 and the module 3 has already acquired the descriptor information Z1 and the descriptor information Z3 from the memory 30, the second information included in the descriptor information Z1 and the descriptor information Z3. The priority is acquired. Therefore, each of the module 1 and the module 3 starts the data transfer of the data Y1 and the data Y3 to and from the memory 30 based on the descriptor information Z1 and the descriptor information Z3. The priority is notified to the arbitration processing unit 81.

First, in step S1, when the arbitration processing unit 81 determines that the use requests of the shared bus 22 by the module 1 and the module 3 are in conflict (Yes side of the step S1), the execution is subsequently performed. In step S2, the arbitration processing unit 81 determines that the second priority has been notified from each of the module 1 and the module 3 (Yes in step S2), and the process proceeds to step S4. As described above, in step S1, whether or not the access request signal to the memory 30 and the use request signal for the shared bus 22 transmitted from the modules 1 to 4 are simultaneously received from a plurality of modules. Thus, it is determined whether or not the use requests of the shared bus 22 are in conflict.
In step S4, the arbitration processing unit 81 notifies the priority order of use of the shared bus 22 by the module 1 and the module 3 from the module 1 and the module 3, respectively. Mediation based on As described above, the second priorities of the module 1 and the module 3 in the present embodiment are “3” and “1”, respectively. Therefore, in the process of step S4, the module 3 is determined to have a higher priority than the module 1, and the module 3 is given the right to use the shared bus 22, and the shared bus by the module 1 is given. 22 usage requests are waited. Thereafter, when the data transfer of the data Y3 between the module 3 and the memory 30 is completed and the shared bus 22 is released, the arbitration processing unit 81 grants the right to use the shared bus 22 to the module 1. The data Y1 is transferred between the module 1 and the memory 30.
As described above, in the system X1, the priority of the modules 1 to 4 when transferring data to and from the memory 30 is the descriptor information indicating information such as the data size of the transferred data Y1 to Y4. Since arbitration is performed according to the second priority included in Z1 to Z4, if the second priority of data having a small data size is set higher than the second priority of data having a large data size. It is possible to execute transfer in ascending order of data size, etc., the data transfer efficiency in the system X1 is improved, and the processing speed of the image forming apparatus equipped with the system X1 is improved. Further, the priority order of the use of the shared bus 22 by the modules 1 to 4 is arbitrated based on the second priority that depends on the descriptor information Z1 to Z4 without depending on the type of the modules 1 to 4. Since it is a structure, it can respond flexibly to the software design in the system X1.

Hereinafter, an embodiment will be described in which the priority of use of the shared bus 22 by the modules 1 to 4 is arbitrated based on a third priority based on the second priority received from the modules 1 to 4. To do.
4 is a block diagram showing a schematic configuration of the system X2 adopting the information transfer method according to the embodiment of the present invention, FIG. 5 is a diagram showing an example of the priority setting table, and FIG. It is a flowchart explaining an example of the procedure of the arbitration process performed.
In addition, the same code | symbol is attached | subjected about the component similar to the said system X1 demonstrated in the said embodiment, and the description is abbreviate | omitted.
As shown in FIG. 4, the arbitration device 18 in the system X2 includes an arbitration processing unit 81 that executes arbitration processing when the use requests of the shared bus 22 by the modules 1 to 4 compete, and the image forming apparatus. An operation mode determination processing unit 82 (an example of an operation mode determination unit) that determines which operation mode is the current operation mode, the operation mode, the second priority, and the third priority. A priority setting table storage unit 83 (an example of a priority setting information storage unit) that stores a plurality of associated priority setting tables T1 to T3, and the plurality of priorities according to the operation mode of the image forming apparatus. A priority setting table selection processing unit 84 (an example of priority setting information selecting means) for selecting any one of the setting tables T1 to T3, and the priority setting A priority setting processing unit 85 (an example of priority information setting means) that sets the third priority based on the priority setting table selected by the table selection processing unit 84 and the second priority; , And is configured.

Here, the priority setting tables T1 to T3 stored in the priority setting table storage unit 83 will be described with reference to FIG.
As shown in FIG. 5, when the operation mode of the image forming apparatus is a print mode, the priority setting table T3 is a print mode, the priority setting table T3 is a print mode. In the simultaneous scan mode, the correspondence between the second priority and the third priority is shown. For example, in the priority setting table T2, when the second priority is “4”, the third priority is “3”, and when the second priority is “2”. The third priority is “1”.

In the system X2 configured as described above, the following processing is executed in the processing corresponding to step S4 in the arbitration processing (S1 to S4) described in the embodiment.
As shown in the flowchart of FIG. 6, first, in step S41, the operation mode discrimination processing unit 82 discriminates the current operation mode of the image forming apparatus. Specifically, the current operation mode of the image forming apparatus is determined by receiving a status signal indicating the status of the image forming apparatus transmitted from the CPU 10 via the BIU 7. Alternatively, the current operation mode of the image forming apparatus is determined by monitoring the rising state of the register indicating the state of the image forming apparatus. Here, the operation mode of the image forming apparatus indicates an operation state of the image forming apparatus such as a scan mode for reading a document image and a print mode for executing print output of a document image.
In step S42, the priority setting table selection processing unit 83 selects a priority setting table corresponding to the type of operation mode determined in step S41 from the priority setting tables T1 to T3. . Specifically, when the operation mode of the image forming apparatus is the print mode, the priority setting table T1 is selected. When the operation mode is the scan mode, the priority setting table T2 is selected, and printing, scanning is performed. In the simultaneous mode, the priority setting table T3 is selected. That is, the priority setting tables T1 to T3 are switched according to the operation mode of the image forming apparatus. Here, the description will be continued assuming that the operation mode of the image forming apparatus is the scan mode and the priority setting table T2 is selected.
Next, in step S43, based on the second priority notified from each of the module 1 and the module 3, and the priority setting table T2 selected in the step S42, the module 1 and the module 1 A third priority for each module 3 is set. That is, the third priority of the module 1 whose second priority is “4” is “3”, and the third priority of the module 3 whose second priority is “2”. Is set to “1”.
In the subsequent step S44, the arbitration processing unit 81 determines the priority of use of the shared bus 22 by the module 1 and the module 3 for which the third priority has been set. Arbitration is based on priority. Here, since the third priority of the module 1 is “3” and the third priority of the module 3 is “1”, the priority of the module 3 is higher and the module 3 has the shared bus. 22 usage rights are granted, and use of the shared bus by the module 1 is awaited.

As described above, in the system X2, the priority setting tables T1 to T3 selected according to the second priority included in each of the descriptor information Z1 to Z4 and the operation mode of the image forming apparatus, Based on the priority of 3 set based on the above, the priority of use of the shared bus 22 by the modules 1 to 4 is arbitrated. That is, in the image forming apparatus, arbitration suitable for each operation mode of the image forming apparatus is performed, and the processing speed in each operation mode can be improved.
A configuration is also conceivable in which the second priority included in each of the descriptor information Z1 to Z4 stored in the memory 30 is changed according to the operation mode of the image forming apparatus. Specifically, the second priority is changed by the CPU 10 and the arbitrating device 8 according to the operation mode of the image forming apparatus. However, in this case, there are concerns about an increase in processing load by the CPU 10 and the arbitrating device 8 that execute the change, and congestion of the bus bandwidth of the shared bus 22 due to the change. However, in the system X2, the arbitration device 8 changes the second priority and the operation mode of the image forming apparatus without changing the second priority included in each of the descriptor information Z1 to Z4. On the basis of this, it is possible to set an appropriate third priority for the operation mode, so that the processing load on the CPU 10 and the arbitrating device 8 is increased, and the bus bandwidth of the shared bus 22 due to the change is increased. Congestion can be prevented.

The block diagram which shows schematic structure of the system X1 by which the information transfer system which concerns on embodiment of this invention was employ | adopted. The figure which shows an example of the descriptor information in this invention. 7 is a flowchart for explaining an example of a procedure of an arbitration process executed by an arbitration processing unit 81. The block diagram which shows schematic structure of the system X2 by which the information transfer system based on the Example of this invention was employ | adopted. The figure which shows an example of a priority setting table. The flowchart explaining an example of the procedure of the arbitration process performed by the arbitration apparatus. The block diagram which shows schematic structure of the system X3 by which the conventional information transfer system was employ | adopted. The figure which shows an example of the conventional descriptor information.

Explanation of symbols

1-4 ... module (an example of a master device)
7 ... BIU
8. Arbitration device (an example of arbitration means)
81. Arbitration processing unit 82 ... Operation mode discrimination processing unit (an example of operation mode discrimination means)
83... Priority setting table storage unit (an example of priority setting information storage means)
84 ... Priority setting table selection processing unit (an example of priority setting information selection means)
85... Priority setting processing unit (an example of priority information setting means)
10 ... CPU
20 ... ASIC
21, 22 ... shared bus 30 ... memory (an example of storage means)
31 ... Descriptor storage area 31a ... Data area 32 ... Data storage areas X1 to X3 ... System Y1 to Y4 ... Data Z1 to Z4 ... Descriptor information S1, S2, ... Processing procedure (step) number

Claims (4)

Storage means for storing a plurality of data and a plurality of descriptor information corresponding to each of the data;
A plurality of data transfer means for transferring data to and from the storage means based on the descriptor information acquired from the storage means;
A shared bus connecting the storage means and the data transfer means;
Arbitration means for arbitrating the priority of use of the shared bus by the plurality of data transfer means based on first priority information preset for each of the plurality of data transfer means;
An information transfer method comprising:
The descriptor information includes second priority information set in advance for each descriptor information;
The data transfer means acquires the descriptor information from the storage means in accordance with the priority of use of the shared bus arbitrated based on the first priority information by the arbitration means, and thereafter, the storage means Notifying the arbitration means of the second priority information when transferring data between
The information transfer characterized in that the arbitration means arbitrates the priority of use of the shared bus by the plurality of data transfer means based on the second priority information notified by the data transfer means method.   The arbitrating means arbitrates the priority of use of the shared bus by the plurality of data transfer means based on third priority information based on the second priority information notified by the data transfer means. The information transfer method according to claim 1. The mediation means is
An operation mode discrimination means for discriminating a current operation mode in the information processing apparatus adopting the information transfer method;
Priority setting information storage means for storing priority setting information corresponding to the operation mode;
Priority setting information selection means for selecting any one of a plurality of priority setting information stored in the priority setting information storage means according to the determination result by the operation mode determination means;
Priority information setting means for setting the third priority information based on the priority setting information and the second priority information selected by the priority setting information selecting means;
The information transfer system according to claim 2, further comprising:   An image forming apparatus comprising the information transfer method according to claim 1.

Images