JP2616419B2 - Information processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus, and more particularly to switching of a reference area during execution of a program for performing a process involving reference to a memory bank area.

[0002]

2. Description of the Related Art With an increase in software in recent years, the size of a program often exceeds a memory space normally accessible to a CPU. In such a case, the program code is usually stored in a non-resident memory called an extended memory, and the program is executed while switching the memory space. In that case, it is important how to switch the reference of the memory bank area in the extended memory. Switching of reference of a memory bank area in a conventional information processing apparatus will be described with reference to the drawings.

FIG. 2A is a memory map showing a configuration example of a memory included in a conventional information processing apparatus. In FIG. 1, a memory included in a conventional information processing apparatus includes a resident unit (normal unit) 20 and an extension unit (non-resident unit) 10. Then, programs 1 and 2 are stored in the resident unit 20.
In addition, programs 3 and 4 and data 2 are stored in the extension unit 10. It is assumed that a vacant area (not shown) exists in the resident unit 20.

[0004] It is assumed that there are a normal mode and an extended mode in the memory access method of the CPU of the information processing apparatus. Then, in the normal mode, the CPU can see that the programs 1 and 2 and the data 1 exist in the resident unit 20, and in the extended mode, the programs 1 to 4 and the data 1
It is assumed that the CPU sees that any three of the two exist in the resident unit 20.

However, it is assumed that the program setting can be changed only in the normal mode. Therefore, when switching the memory bank area to be referred to in the extended mode, it is necessary to temporarily return to the normal mode, and in such a case, the memory cannot be temporarily referred to.

An operation in the case where the CPU of the information processing apparatus including the memory having such a configuration executes the program 3 and the program 3 transitions from the data 1 reference state to the data 2 reference state will be described.

When the program 3 is executed, the program 3 must be moved from the extension unit 10 to the resident unit 20. Further, the data 1 to be referred must also be moved from the extension unit 10 to the resident unit 20. The state after this movement is shown as state A in FIG. The state after the transition from the reference state of data 1 (state A) to the reference state of data 2 is shown as state B in FIG.

Here, the transition from the state A to the state B in FIG. 1B can be performed by changing the program setting of the memory in the program 3, but the setting change of the program is performed only in the normal mode as described above. Can not do. Therefore, once the mode is returned to the normal mode, the program 2 changes from the state A to the normal mode while the execution point Y of the program remains unchanged, as shown in FIG. .

In order to prevent this runaway, in the conventional information processing apparatus, the program setting change section (memory bank switching processing section) is always provided in the program 1 (resident section). In this case, the transition from the state A to the state B is performed in the following procedure.

That is, as shown in FIG. 3, the program 3 is first moved from the extension unit 10 to the resident unit 20, and then the program 3 is executed. At this time, data 1 and programs 1 and 2 are stored in the resident unit 20, and the execution point of the program is Y (step 21).

When the reference area of the memory bank is switched during the execution of the program 3, a call 31 of the memory bank switching processing section (subroutine) included in the program 1 is performed, and the execution point Y moves. (Step 2
2).

Here, when the switching 32 of the reference area of the memory bank is performed, the normal mode is set once (step 2).
3) Data 1 is switched to data 2 by the operation of the memory bank switching processing unit (step 24).

When a return 33 is made from the operation of the memory bank switching processing section, the program execution point Y returns to the original point (step 25).

By the above operation, the reference area of the memory bank is switched, but the method of calling 31 of the memory bank switching processing unit becomes a problem. That is, since the program 1 and the program 3 cannot be generally linked, it is not known where the program 1 is located in the program 1. Therefore, in order to solve this, the calling 31 of the memory bank switching processing unit has been performed by one of the special calling procedures by the following two methods.

The first method is a method using a software interrupt. That is, this is a method in which the program 1 describes the address of the memory bank switching processing unit in the interrupt destination address, and the program 3 refers to this.

The second method is a method in which the address of the memory bank switching processing section is fixed, the program 1 is always arranged at that address at the start address of the memory bank switching function, and the address is called by the program 3.

[0017]

According to the above two methods, the memory bank switching processing unit can be called. However, according to the first method, there is a disadvantage that software interrupt vector resources are consumed, and according to the second method, when the mapping of the resident unit is changed, the influence is extended to the extension unit.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional disadvantages, and an object of the present invention is to provide an information processing apparatus capable of switching a reference area of a memory bank without performing a special calling procedure. It is to be.

[0019]

An information processing apparatus according to the present invention includes a resident memory, an extended memory including first and second memory bank areas, and the first and second resident memories executed in the resident memory. An information processing apparatus having a program for performing processing involving reference to a memory bank area,
Switching means for switching a reference area, which is held in the extended memory and referred to by the program, of the first and second memory bank areas, and which is retained in the extended memory and is resident when the reference area is switched Acquiring means for acquiring a predetermined area of the memory; and copying means for copying the switching means to the acquired area held by the extended memory and acquired by the acquiring means, wherein the switching means copied to this area makes the reference. It is characterized in that the area is switched.

[0020]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of an information processing apparatus according to the present invention, and portions equivalent to those in FIG. 2 are denoted by the same reference numerals. Referring to FIG. 1, an information processing apparatus according to an embodiment of the present invention includes an extension unit 10 in which a data unit and a program unit are stored.

The data section of the extension section 10 includes memory bank areas 7 and 8. Also, the extension unit 10
The program section includes an application program 3 for performing processing involving switching of a memory bank area to be referred to, a memory bank switching reception processing section 100 for performing processing for switching memory banks, and a memory bank switching processing section included in the processing section 100. A code body 200, a resident memory acquisition unit 300 for acquiring a predetermined area 40 of the resident memory 20, and a memory copy execution unit 400 for copying the memory bank switching code body 200 to the area 40 acquired by the memory acquisition unit 300. It is comprised including. Note that the memory bank switching reception processing unit 100 and the resident memory acquisition unit 30
0 and the memory copy execution unit 400 are in the form of a subroutine.

Consider a case in which the memory bank area 7 being referred to is switched to another memory bank area 8 while the application program 3 is executing in the resident unit in the extended mode operation of the information processing apparatus having such a configuration.

In this case, the program 3 calls the memory bank switching reception processing unit 100 in the extension unit to switch the memory bank area to be referred to (). After receiving this request, the memory bank switching reception processing unit 100 first calls the resident memory acquisition unit 300 (), and acquires the necessary area 40 in the resident memory 20 ().

Memory bank switching reception processing unit 1 receiving return () after acquisition of area 40 in resident memory 20
00 calls the memory copy execution unit 400 (), and owns the memory bank switching code body 2
00 is copied to the area 4 (). Upon receiving the return () after the copy, the memory bank switching reception processing unit 100 calls the copied memory bank switching code body 200 ().

The called memory bank switching code body 200 is executed on the resident memory 20 and switches the memory bank area 7 to the memory bank area 8. After the execution of the switching, the memory bank switching code body 200 returns () to the memory bank switching reception processing unit 100.

Finally, the memory bank switching reception processing unit 1
00 releases the acquired area 40, and returns ([10]) to the program 3. Thus, the switching process of the memory bank area is completed.

In short, in the present invention, the area in the resident section is acquired from the extension section, and the code for switching the memory bank is copied and executed in the acquired area, without using any special calling procedure. Thus, the memory bank can be switched. As a result, the software interrupt vector resources are not consumed, and the effect of the change in the mapping of the resident part does not spread to the extension part.

[0029]

As described above, the present invention obtains an area in the resident section from the extension section, copies the code for switching the memory bank to the obtained area, and executes the code. There is an effect that the memory bank can be switched without using the memory bank.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a main part of an information processing apparatus according to an embodiment of the present invention.

FIG. 2A is a memory map showing a configuration example of a memory included in a conventional information processing apparatus, FIG. 2B is a memory map showing a transition from a reference state of data 1 to a reference state of data 2, c) is a memory map showing the state transition when changing the program setting of the memory.

FIG. 3 is a conceptual diagram showing a state transition of a memory when a memory bank area is switched in a conventional information processing apparatus.

[Explanation of symbols]

 Reference Signs List 3 application program 7, 8 memory bank area 10 extension section 20 resident section 40 area 100 memory bank switching reception processing section 200 memory bank switching code body 300 resident memory acquisition section 400 memory copy execution section

Claims (2)

(57) [Claims] 1. A resident memory, an extended memory including first and second memory bank areas, and a program executed in the resident memory and performing processing involving reference to the first and second memory bank areas. A switching means for switching a reference area of the first and second memory bank areas that is referred to by the program and held in the extended memory; and An acquisition means for acquiring a predetermined area of the resident memory when the reference area is switched; and a copy means for copying the switching means to an acquisition area held in the extended memory and acquired by the acquisition means. An information processing apparatus for performing switching of the reference area by switching means copied in the information processing apparatus. 2. The information processing apparatus according to claim 1, further comprising: means for releasing the acquired area after switching the reference area by the copied switching means.