JPH06259319A - Extended memory program using function - Google Patents

Abstract

PURPOSE:To utilize the memory space of an extended memory exceeding the limits of the memory space by providing a substitute actuation part which is actuated instead of a user program and transfers it to a physical memory and accesses the memory in the extended memory. CONSTITUTION:A transfer part 7 secure an area in the extended memory 6 and transfers a user program 4a, which processes user's transaction to the area in the extended memory 6. In this case, when the user program 4a is to be actuated, the substitute actuation part 8 is actuated instead of the user program 4a and requests an extended memory control system 3 to transfer the user program 4a to the physical memory 5 and enable access, thereby actuating the user program 4a. After the user program 4a ends, the substitute actuation part 8 is returned from the user program 4a. The substitute actuation part 8 is further returned to a called destination. Therefore, the same result with the operation of the user program 4a on the physical memory 5 is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an extended memory program utilization function.

[0002]

2. Description of the Related Art Recent advances in semiconductor technology have made it easier to use microprocessors, and many electronic devices have come to utilize them.

At present, a microprocessor having a word length of 16 bits has become widespread and is used as a processing unit of a so-called personal computer. However, since a microprocessor having a word length of 16 bits can only allocate 20 bits to specify the memory space as its limit, only 1 megabyte of memory space can be specified.

Further, 6 of this 1 megabyte memory space is used.
Since an address of 40 kilobytes or more is specified in the specifications for hardware only, a personal computer user needs to create and operate a program in a memory space of 640 kilobytes or less (called a convention memory).

Therefore, in order to provide a larger amount of memory space, an extended memory management specification is proposed jointly with a manufacturer of 16-bit microprocessors and a plurality of software vendors, and each vendor proposes a system (hereinafter referred to as EMM). For short) is now available.

This EMM is provided with a special function to connect an extension memory, and the extension memory space is paged to 64 kilobytes (hereinafter abbreviated as KB) of a dedicated hardware space of 640 kilobytes or more, so that 32 It is possible to connect and use extended memory up to megabytes. In this case, the hardware cannot use that memory space. The operation of the EMM will be described below.

FIG. 6 is a memory circuit configuration diagram of a 16-bit MPU. In the figure, 10 is a 16-bit MPU which uses the expansion memory 6 via the physical memory 5 and the expansion memory access circuit 11.

2 is a disk operating system (
Hereinafter, abbreviated as DOS), which is a program for controlling execution of the 16-bit MPU 10. An EMM 3 is a program for instructing the extended memory access circuit 11 to transfer a necessary memory space divided into pages between the physical memory 5 and the extended memory 6 and to manage the page. . Reference numeral 4 is a user program, which is a program for which the extended memory 6 is desired to be used.

A physical memory 5 is a 16-bit MP.
It is a memory that U10 can directly access. Reference numeral 6 denotes an expansion memory, which is a memory added in addition to the physical memory 5 and which can be accessed only through the expansion memory access circuit 11 and can be connected up to 32 megabytes.

Reference numeral 11 denotes an extended memory access circuit,
This is a circuit that transfers data between the physical memory 5 and the extended memory 6. Therefore, the user program is
Extended memory access circuit when accessing the contents of
11 must be transferred to physical memory 5 before it can be accessed. FIG. 7 is a diagram for explaining the operation of the extended memory management system.

In the figure, reference numeral 21 denotes a memory management table, which is a table in which the EMM 3 manages the pages of the extended memory 6 and the pages of the user program 4 and the hardware dedicated area of the physical memory 5 in association with each other.

A transfer function 22 is a program for instructing the extended memory access circuit 11 to transfer data between the physical memory 5 and the extended memory 6 at the request of the user program 4, and is a part of the EMM3. Is.

Reference numeral 23 denotes an allocation function, which allocates an empty page of the expansion memory 6 to the user program 4 at the request of the user program 4, and is a part of EMM3. Reference numeral 31 is a normal area, which is a memory space in the convention memory.

Reference numeral 32 denotes an extension area in hardware,
This is an area for storing the user program 4 transferred from the area 33 in the expanded memory by the EMM 3. Reference numeral 33 denotes an area in the extended memory, in which the user program 4 is stored.

When the user program 4 uses the expansion memory 6, it first requests the EMM 3 to allocate the expansion memory 6 (the operation in the figure, the requested amount is 2 pages). E
The allocation function 23 of the MM3 refers to the memory management table 21, and if there is a free page, allocates the page (pages 0036 and 0037 in the figure) to the user program 4, writes it in the memory management table 21, and writes it to the user program 4. The page number (0036, 0037
Page).

If there is a page that the user program 4 wants to use, the page number (from the user program 4 to the EMM 3
(Page 0036) and request transfer (operation in the figure).
The transfer function 22 of the EMM3 transfers the page of the specified expansion memory 6 (that is, the expansion memory internal area 33) to the specified internal expansion area 32 of the hardware.

Since the user program 4 can access the area within 1 megabyte, it can directly access the extension area 32 in the hardware (the operation shown in the figure). Also,
If other data is needed, its page number (for example, 0037
Page) is notified to the transfer function 22 of the EMM3 and transferred to the designated expansion area 32 in the hardware, and conversely, the data written in the expansion area 32 in the hardware is transferred to the allocated page of the expansion memory 6. You can also

Further, in the above description, the physical memory used by the extended memory management system is provided in the dedicated hardware area, but it may be provided in the convention memory. The hardware can be used without any restrictions.

Further, when it is desired to use the extended memory 6, it is necessary to incorporate a process for requesting the EMM 3 in the user program 4.

[0020]

However, a program created before this system was provided cannot obtain such a benefit. However, it is common to combine a plurality of programs created in the past to form a new function. At that time, all of the programs created in the past may not fit in the 640 kilobyte convention memory.

Therefore, there is a demand for a technique for using these programs in the extended memory 6 without making any changes to use the EMM3. In view of such a point, the present invention has an object to provide a means for using a conventional program in the extended memory without making a change for using the extended memory.

[0022]

The above-mentioned problems can be solved by the extended memory program utilizing function configured as follows.

FIG. 1 shows the principle of the present invention. Microprocessor 20, physical memory 5 accessed by the microprocessor 20, extended memory 6 connected to the microprocessor 20, and extended memory access circuit for performing transfer between the extended memory 6 and the physical memory 5 In a microprocessor system having 11 and an extended memory management system 3 capable of accessing the extended memory 6 by using the extended memory access circuit 11, an area is secured in the extended memory 6 and a user's work is processed. User program
When the user program 4a and the transfer unit 7 that transfers 4a to the area of the extended memory 6 are about to be started, it is started instead of the user program 4a, and the extended memory management system 3 is requested to request the user program 4a. Program 4a in the physical memory
5 to enable access and to activate the user program 4a, and to return from the user program 4a after the end of the user program 4a.

[0024]

[Operation] The transfer unit 7 secures an area in the expansion memory 6 and executes the user program 4a for processing the user's work.
To the area.

When the user program 4a is about to be activated, the proxy activation unit 8 activates instead of the user program 4a and requests the extended memory management system 3 to transfer the user program 4a to the physical memory 5. The user program 4a is started by transferring it so that it can be accessed.

After the end of the user program 4a, the proxy activation unit
Return from the user program 4 to 8. Proxy activation unit 8
Returns to the called party. Therefore, the same result as when the user program 4a operates on the physical memory 5 is obtained, and the extended memory 6 can be used without changing the conventional user program 4a.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The target user program here is a program activated by an interrupt, and it is premised that the user program is left in the physical memory after the processing is finished and is activated again.

FIG. 2 is a system configuration diagram using the program utilizing function of one embodiment of the present invention. In the figure, 4
Reference numeral a is a user program for processing the user's business and not using EMM3. Reference numeral 9 denotes an extended memory program utilization function, which comprises a transfer unit 7 and a proxy activation unit 8.

Reference numeral 7 denotes a transfer unit, which is a user program 4a which secures an area in the extended memory 11 and processes the user's business.
Is transferred to the area of the extension memory 11. Reference numeral 8 denotes a proxy activation unit, which is activated instead of the user program 4a when the user program 4 is about to be activated,
Request the extended memory management system 3 to transfer the user program 4a to the physical memory 5 so that it can be accessed, activate the user program 4a, and return to the caller when returning from the user program 4a. It is a thing.

FIG. 3 is an operation flowchart of the transfer unit according to the embodiment of the present invention. FIG. 4 is a transition diagram of the memory area according to the embodiment of the present invention. The operation of one embodiment of the present invention will be described using both drawings. FIG. 4A is a diagram showing an initial memory area, and the convention memory has D
There are OS2, EMM3, and transfer unit 7 of the extended memory program utilization function 9 (the user program 4a is loaded later). The operation of the transfer unit will be described below with reference to the flowchart. First, at step 70, the size and start position of the area (free area) of the physical memory 5 which is not currently used is checked by checking the table managed by DOS2.

Next, at step 71, the user program 4a is loaded. In step 72, the size and start position of the free area are checked again. In step 73, the size of the user program 4a is obtained from the difference between the size of the free area in step 70 and the size of the free area in step 72.

Next, in step 74, the expansion memory 6 is added to the EMM3.
The area is requested to be secured in order to transfer the user program 4a. EMM3 notifies the transfer unit 7 of the secured page number. In step 75, the interrupt start position of the user program 4a is obtained. The interrupt start position is an address where the operation of the user program 4a is started.

In step 76, the user program 4a is transferred to the area of the physical memory 5 managed by the EMM 3 (area corresponding to the expanded area in the hardware of FIG. 7). The original area is made empty. The diagram after transfer of the transfer unit in FIG.
The state of the memory area at this time is shown.

In step 77, the EMM 3 is requested and the user program 4 a is transferred to the extension memory 6. In step 78, the proxy activation unit 8 is loaded so that the interrupt start position is the same as the user program 4a. EM of FIG. 4 (C)
The figure after M transfer shows the state of the memory area at this time.

In step 79, the proxy starting unit 8 is notified of the interrupt start position of the user program 4a. This is because the user program 4a is in the extended memory 6 and therefore the address when it is brought to the physical memory 5 must be specified in order to interrupt.

The user program 4a is now stored in the expanded memory.
Since it was transferred to 6, the proxy startup unit 8 and the user program
The area of the convention memory is vacated by the difference in size of 4a.

The operation when the user program 4a thus transferred to the extended memory 6 is activated will be described. FIG. 5 is an operation flowchart of the proxy activation unit according to the embodiment of the present invention. The operation of the proxy activation unit will be described with reference to the drawing.

First, when an interrupt start position of the user program 4a is designated by another program (not shown) and an interrupt occurs, the proxy start unit 8 is stored at that position by the operation of the transfer unit 7. Therefore, the proxy activation unit 8 starts operating.

In step 80, the EMM3 user program
Request to transfer 4a to the area of physical memory 5 managed by EMM3. EMM3 is the designated user program 4a
To the area of the physical memory 5 managed by EMM3.

At step 81, the interrupt start address of the user program 4a notified at step 79 of the transfer unit 7 is interrupted,
Operate the user program 4a. User program 4a
When execution ends, returns to step 82 by interrupt return.

The interrupt is returned to the caller interrupted in step 83. Needless to say, the same effect can be obtained by executing the interrupt and the interrupt return with different equivalent instructions.

The user program described above does not need to be created by the user. However, it is necessary that the instructions that use EMM3 are not included.

[0043]

As is apparent from the above description, according to the present invention, there is a remarkable industrial effect that various existing programs can be used beyond the limit of the memory space without modification.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a system configuration diagram using an extended memory program utilization function according to an embodiment of the present invention.

FIG. 3 is an operation flowchart of a transfer unit according to an embodiment of the present invention.

FIG. 4 is a transition diagram of a memory area according to an embodiment of the present invention.

FIG. 5 is an operation flowchart of a proxy activation unit according to an embodiment of the present invention.

FIG. 6 is a memory circuit configuration diagram of a 16-bit MPU.

FIG. 7 is a diagram for explaining the operation of the extended memory management system.

[Explanation of symbols]

2 DOS 3 EMM 4, 4a User program 5 Physical memory 6 Extended memory 7 Transfer section 8 Proxy activation section 9 Extended memory program utilization function 10 16-bit MPU 11 Extended memory access circuit 20 Microprocessor 21 Memory management table 22 Transfer function 23 Allocation function 31 Normal Area 32 Extended Area in Hardware 33 Extended Memory Area 70 to 82 Operation Steps

Claims (1)

[Claims] 1. A microprocessor (20), a physical memory (5) accessed by the microprocessor (20), and an expansion memory (6) connected to the microprocessor (20),
An extended memory access circuit (11) for transferring between the extended memory (6) and the physical memory (5), and the extended memory (6) can be accessed by using the extended memory access circuit (11) In a microprocessor system having an extended memory management system (3), a user program (4a) that secures an area in the extended memory (6) and processes user tasks is transferred to the area of the extended memory (6). When the transfer unit (7) and the user program (4a) are about to be started, the transfer unit (7) is started instead of the user program (4a) and the extended memory management system (3) is requested to request the user program (4a). 4a) is transferred to the physical memory (5) so that it can be accessed,
The user program (4a) is started and the user program (4a)
a) An extended memory program utilization function, characterized in that it has a proxy activation unit (8) that returns from the user program (4a) after completion.