KR19980048819A - Electronic control system with memory saving and memory saving method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory saving method of a general electronic control system. In the memory operating method using a plurality of banks connected in parallel to the same microcomputer, the same constant region occupies each root region of a plurality of ROMs. It relates to a memory saving method in the root area of a ROM that can be prevented.

The process of creating constant variables in a separate file, the process of compiling and linking a plurality of program sources into a separate constant file, and the bank in which the constants are stored The process of searching for and finding the address where a certain constant is stored in the corresponding bank proceeds to save the constant area, which is duplicated and stored in the root area in a specific bank, in the nested bank memory model, thereby reducing the root area and increasing the space for programming. It can have an effect.

Description

Electronic control system with memory saving and memory saving method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory saving method of a general electronic control system. In the memory operating method using a plurality of banks connected in parallel to the same microcomputer (MPU), the same constant is applied to each root region of a plurality of ROMs. The present invention relates to a memory saving method in a root area of a ROM that can prevent an area from being occupied.

First, to describe the operation principle of a generally used electronic system, the simple configuration shown in FIG. 1 will be referred to.

A microprocessor (hereinafter referred to as a microcomputer) used as a central processing unit or a system controller, and a control program to be provided to the microcomputer 10. A memory device 20 which is used as a temporary storage of data, an input / output unit 30 which is responsible for input / output of signals according to the control signal of the microcomputer 10, An input device 31 serving as a source for providing an input signal to the input / output unit 30 and an output device for implementing the operation through the input / output unit 30. Device) 32.

The memory device 20 may include a read / write random access memory (RAM) and a read only memory (ROM). ROM does not disappear even if the power is cut off. Therefore, such a ROM (ROM) is to provide the information on the operation to be processed by the microcomputer 10 at the same time the power supply.

Here, the details stored in the ROM will be described in more detail. 2 shows a memory structure MAP of a ROM. As shown

ROM is divided into root area and program source area. Root of ROM includes startup code 201, Interrupt Service Routine (202) and Common Routine (203), function functions (204) and constants that require fast processing speed. It consists of a storage area 205.

On the other hand, the address area of the ROM that can be controlled by the microcomputer is limited. For example, in the case of 8051, the original use area is 0000H to FFFFH, which is 64 KByte. As the root area becomes larger, the address space for the bank is reduced, and as a result, the space for program code to enter the bank area (or program source area) is reduced.

To overcome this, a plurality of ROMs are connected in parallel as shown in FIG. 3. The model to which this method is applied is called the Banked Memory Model.

In other words, the Interrupt Service Routine (ISR), the startup code, the constant region, and other routines commonly used in various banks are used for the root region, and a routine that requires fast execution is used.

Other program sources are stored in the bank area. At this time, each bank is placed in the same address space.

Bank selection is controlled by the microcomputer's output port during a function call.

Here, in each root area Root, constant areas 205 are duplicated and stored from the same details, that is, the startup code 201. Constant Variables are variables that are not changed during the program among Variables and are stored in ROM rather than RAM. In the case of the banked memory model, the root region is unconditionally included.

In this case, when the root area becomes larger, the bank area becomes relatively small, and many banks are used, thus occupying as many microcomputer ports. Frequent bank switching at the microcomputer will degrade the system's practical efficiency.

An object of the present invention is to secure a wider bank area so that a larger program source can be input to a bank by reducing the size of a root of a ROM.

Another object of the present invention is to reduce the size of the root region by moving a constant region, which is commonly occupied in each root region, to a bank region.

It is easy to move the function to the banked area among the elements that enter the root area, but it loses its original meaning of putting the function into the root area.

A feature of the present invention for achieving this purpose is to store a banker and an address in which a constant is stored in a root area, and store details of actual constants in a plurality of banks in a root area of a ROM. The purpose is to prevent the constant storage area from overlapping.

In addition, the characteristic of the specific implementation method is the process of creating a constant (Constant Variable) as a separate file, and by compiling and linking a plurality of program sources (Combining) to a separate constant file And the process of finding a bank in which a constant is stored and finding an address in which a specific constant is stored in the bank.

1 is a block diagram showing the basic configuration of a general electronic device system;

2 is a memory structure diagram of a ROM;

3 is a block diagram of a conventional banked memory model signal processing structure;

4 is a memory structure diagram of a ROM according to the present invention;

5 is an operational flowchart showing an implementation method of the present invention.

4 is a block diagram illustrating a structure of a memory according to an embodiment of the present invention. As shown, unlike the conventional memory structure, it can be seen that the constant variable area is not in the root area but in the bank area, that is, the program source area.

At this time, the root area should store a bank number and an address including a constant.

More specifically, the root region of each ROM requires a startup code 201, an interrupt service routine (ISR) 202, a common routine 203, and a fast processing speed. A function 204 is included.

Each bank area includes a program for operating the microcomputer 10 and a constant area is located in a specific bank.

An execution process for this configuration will be described with reference to the flowchart of FIG. 5.

First, make a constant variable file separately (S1).

Each program source is compiled (S2). At this time, the constant variable is excluded.

The plurality of object files (* .obj) generated by the compilation (S2) are linked to each other (S3).

The file generated through the compilation / linking step S2 / S3 and the constant variable file provided separately (S1) are merged (S4).

At this time, the constant variable should be put in a specific address of a specific bank. The programmer also needs to know the number and address of this bank.

The method of accessing a constant in a program in a ROM created by the above process proceeds as follows.

Declare one or more pointers to find the bank where the constant required by the program is located (S5).

The address in which the specific constant is located in the specific bank is found (S5).

The address of the found constant is copied to the main memory (RAM) and used (S6).

In the nested bank memory model, the constant area, which is duplicated in the root area, is stored in a specific bank, thereby reducing the root area and increasing the space for programming.

Claims (5)

A microcomputer 10 representing an operation control signal throughout the apparatus, A ROM for providing a program necessary for the operation of the microcomputer 10 to the microcomputer 10; In the electronic control system including a RAM (RAM) is stored in the data necessary to execute the program according to the control signal of the microcomputer 10, And a constant region is stored in a bank region by excluding a constant region from a root region of the ROM. The method of claim 1, The microcomputer has a data transfer rate of 16 bits. The method of claim 1, The size of the ROM (ROM) is an electronic control system, characterized in that 64K bytes. In a memory operation method using a plurality of banks connected in parallel to the same microcomputer (MPU), a banker and an address in which constants are stored are stored in a root area, and details of actual constants are stored in a plurality of banks. A method of saving memory in an electronic control system that can save memory by preventing the constant storage area from overlapping in the root area of a ROM by storing the data in a memory. Creating a constant variable in a separate file, Compiling a plurality of program sources (Program Source), Linking a plurality of compiled object files with each other, Merging a constant file provided separately from a file generated through the compilation / linking step; Allowing a pointer variable to represent an area of the bank containing a particular constant; Finding the address of a specific constant actually used in the bank, A method for saving memory in an electronic control system, comprising copying the address of a found constant to main memory (RAM).