JPH05346854A - Operation processor - Google Patents

Abstract

PURPOSE:To execute the arithmetic of a partial program on a sub routine program. CONSTITUTION:A symbol mark is described at the leading position of the partial program on the subroutine program. In the case of reading a program instruction from a user program memory 30 and executing it by a CPU 10, the CPU 10 retrieves the symbol mark on the user program 30 and detects the storage position of the partial program when the CPU 10 detects that the read program instruction is the executing instruction of the partial program. The CPU 10 reads the partial program from the detected storage position and executes the arithmetic.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arithmetic processing unit for sequentially reading out program instructions stored in a program memory and executing arithmetic operations.

[0002]

2. Description of the Related Art A programmable controller for automatically controlling electronic equipment has a central processing unit (CPU) therein, and the above-mentioned automatic control is performed by a coser creating and executing a sequence program. Since the sequence program is created in the form of a circuit diagram and is composed of an intermediate language of an instruction code indicating a circuit symbol, the sequence program is executed after the intermediate language is translated into a machine language executable by the CPU. A sequence program may be created in a programming language that uses mnemonic expressions.

In such a sequence program,
The CPU executes a subroutine program different from the main program according to a subroutine execution instruction written on the main program. However, partial programs on the subroutine program cannot be read and executed separately.

[0004]

For this reason, conventionally, there has been a need for a method for creating a program in which a subroutine program is divided and a plurality of subroutine programs are selectively used. As a result, a large number of subroutine programs are included in the sequence program created, and it is difficult for the coser to understand the relation of inclusion or absence and the relation of inclusion of the subroutine programs.

SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to provide an arithmetic processing unit capable of reading and executing a program instruction in an arbitrary designated range on a program.

[0006]

In order to achieve such an object, the present invention provides an arithmetic processing means for sequentially reading out a program stored in a program memory in program instruction units and executing arithmetic operations, and an arithmetic processing means in the program. , A symbol mark indicating the range of the partial program by describing at the beginning and the end position of the partial program, and a special program instruction for instructing the execution of the partial program in the range indicated by the symbol mark are predetermined and read from the program memory. Determining means for determining whether the program instruction is the special instruction, and the position of the partial program by searching the symbol mark in the program memory when the determination result of the determining means is affirmative. Based on the position of the detected partial program and the search means for detecting Characterized in that the program comprises an arithmetic control means for executing the arithmetic processing means.

[0007]

In the present invention, when the symbol mark is described at the beginning and the end of the partial program to be executed in a subroutine, the symbol mark in the program memory is searched by the searching means when the special program instruction is executed, The position of the partial program, for example, the storage address of the program memory is detected. The arithmetic control means detects this storage address. The arithmetic control means can execute a partial program in a subroutine program or the like in the program by causing the arithmetic control means to execute an operation from the program instruction of the storage address.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows the basic configuration of an embodiment of the present invention. In FIG. 1, reference numeral 1100 is an arithmetic processing means for sequentially reading out programs stored in the program memory 1000 in program instruction units and executing arithmetic operations.

In the present embodiment, by describing at the beginning and end positions of the partial program in the program, a symbol mark indicating the range of the partial program and a special instruction for instructing execution of the partial program in the range indicated by the symbol mark Program instructions are predetermined. Reference numeral 1200 is a determination unit that determines whether or not the program read from the program memory is the special program instruction.

Reference numeral 1300 is search means for detecting the position of the partial program by searching the symbol mark in the program memory when the result of the judgment by the judgment means is affirmative. Reference numeral 1400 denotes an arithmetic control unit that causes the arithmetic processing unit to execute the partial program based on the position of the detected partial program.

FIG. 2 shows a circuit configuration of an arithmetic unit of a programmable controller to which the present invention is applied. In FIG.
The CPU 10 sequentially reads out the sequence program created by the coser from the coser program memory 30 in units of program instructions and executes the operation. At this time, the CPU 10 translates the intermediate language program instructions into a machine language according to the system program in the system program memory 20, and executes the machine language. Such a calculation method is called an interpreter. The control procedure of FIG. 3 for executing the arithmetic processing according to the present invention is stored in the system program memory 20 in advance.

The arithmetic processing operation of the CPU 10 according to the present invention will be described below with reference to the flowchart of FIG. In the present embodiment, a special program instruction (referred to as a symbol mark execution instruction) for instructing execution of a program in a specific range of the sequence program is predetermined.
The symbol mark execution instruction is composed of an instruction code indicating the instruction content and a symbol code indicating the program to be executed.

When a program part to be executed, more specifically, a part located in the middle of a subroutine program to the end of the subroutine program is to be executed, a symbol mark is previously set at the head position of this partial program. Please note. At the end position of the partial program, the subroutine end instruction substitutes for the symbol mark. Further, the symbol mark execution instruction is described at a position in the sequence program where this partial program is desired to be executed. An example of such a sequence program is shown in FIG.

FIG. 4 shows that the symbol mark execution instruction is stored in the address AO + 3 on the user program 30 and the symbol mark is stored in the address BO + 1. The CPU 10 of FIG. 2 activates the control procedure of FIG. 3 at the operation timing of the sequence program. First, the CPU 10 initializes the program execution address at the head of the user program memory 30, and reads the program instruction from the address on the user program memory 30 indicated by the program execution address (steps S10 → S20 in FIG. 3).

Next, in order to translate the program instruction, the content of the read program instruction is identified. In the present embodiment, the content identification is performed by comparing and comparing the read program instruction with various executable program instructions. First, the CPU 10 determines whether or not the read program instruction is a symbol mark execution instruction (step S30 in FIG. 3).

The CPU 10 at the time of performing this determination process operates as the determination means of the present invention. When a negative determination is obtained, the CPU 10 shifts the execution procedure to Tesp S200, and performs a determination process of matching with another program command. In this way, when the match determination is obtained, the CPU is operated as usual.
10 reads out a machine language program instruction group corresponding to the program instruction from the system program 20 and executes it.
After this, the CPU 10 sets the program execution address to "1".
Update and read the next program instruction to be executed from the user program memory 30 (step S210 in FIG. 3 →
S20). Hereinafter, the CPU 10 executes the above step S210.
→ S20). Hereinafter, the CPU 10 performs the above step S30.
The loop process of S200, S210, and S20 is repeated to sequentially execute the program instructions on the user program 20. When the program execution address is set to AO + 3 and the symbol mark execution instruction (see FIG. 4) is read from the user program memory 30 (step S20 in FIG. 3), it is determined that the read program instruction is the symbol mark execution instruction. Identified at 30. Therefore, the CPU 10 detects by searching the partial program whose position is designated by the symbol mark in the subroutine program. More specifically, after temporarily storing the current program execution address value AO + 3 in an internal register, a read address is set in the head area of the user program memory 30 storing the subroutine program,
The program instruction is read from this read address. (Step S50 of FIG. 3). The CPU 10 compares the read program instruction with the symbol label (code) for coincidence, and determines whether the read program instruction is the symbol label (step S60 in FIG. 3).
When a negative determination is obtained, the read address is updated, and the determination process is performed for the next program instruction (steps S70 → S50 → S60 in FIG. 3).

CP when executing such search processing
U10 operates as the snooping means of the present invention. In the example of FIG. 4, when the program instructions are sequentially read from the address BO of the user program memory 20 and the symbol mark (code) of the address BO + 1 is read, S of FIG.
A match determination is obtained at 60. Therefore, the CPU 10 as the arithmetic control means of the present invention sets a value obtained by adding "1" to the read address at this time, BO + 2, to the program execution address, and then as the arithmetic processing means of the present invention, the program next to the symbol mark. Instructions are read out, converted into machine language, and executed (steps S110 → S120 →
(S140 → S150 → S110 loop processing) In this way, when the designated partial program in the subroutine program is executed and the last subroutine end instruction (also referred to as a return instruction) is detected (step S12 in FIG. 3).
0), the CPU 10 returns the program execution address to a value obtained by adding “1” to the temporarily stored AO + 3 (the value of the address at which the instruction next to the symbol mark execution instruction is stored), and the program in the user program memory 20. The instruction reading process (step S20 in FIG. 3) is restarted.

After that, the CPU 10 restarts the operation from the program command of the address of AO + 4, and ends the control procedure by the end command of the main program (see FIG. 4). (Fig. 3
Steps S20 → S30 → S200 → S210 → S2
0 loop processing). By executing such a processing procedure, it is possible to execute a partial program in a subroutine program, which has been impossible in the past.

In addition to this embodiment, the following example can be carried out. 1) In this embodiment, the partial program designated by the symbol mark is limited to the program on the subroutine program, but the partial program on the main program can be called and executed. In this case, a mark indicating the start position and a mark indicating the end position of the partial program are prepared as the symbol mark, and when the program execution instruction is detected, the CPU 10 searches the start address of the user program for the start mark and detects the detected start mark. Execute the partial program between the and end marks. After this, CP
It is the same as the present embodiment that the U10 resumes the execution of the program instruction next to the symbol mark execution instruction. 2) If the symbol mark indicating the position of the partial program is simply used as a character / symbol, an instruction (pseudo-instruction) for specifying the position is prepared, and the symbol mark is added after this instruction. When the pseudo instruction is not added, the CPU 10 handles the symbol mark as a character or a symbol.

[0020]

As described above, according to the present invention, not only the subroutine program but also a partial program at an arbitrary position on the main program can be called and executed. Therefore, it is necessary to divide the subroutine program as in the conventional case. Nor. Therefore, the effect that the user can easily understand the created program content is obtained.

In addition, the same program (sequence)
Since there is no need to describe it in a plurality of places on the program, there is an effect that the creation of the (sequence) program is simplified.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a programmable controller to which the present invention is applied.

FIG. 3 is a flowchart showing a processing procedure executed by a CPU 10 of FIG.

FIG. 4 is an explanatory diagram showing the contents of a program to be executed.

[Explanation of symbols]

 10 CPU 20 System Program Memory 30 User Program Memory

Claims (1)

[Claims] 1. A calculation processing means for sequentially reading a program stored in a program memory in program instruction units and executing the calculation, and a range of the partial program by describing at the head and end positions of the partial program in the program. Show. Determination means for determining in advance a special program instruction for instructing execution of a partial program in the range indicated by the symbol mark and the symbol mark, and determining whether or not the program instruction read from the program memory is the special program instruction; When the determination result of the determination means is affirmative, the search means for detecting the position of the partial program by searching the symbol mark in the program memory, and the position based on the detected position of the partial program, An arithmetic processing unit comprising arithmetic control means for causing the arithmetic processing means to execute a partial program.