JP2833933B2 - In-circuit emulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-circuit emulator, and more particularly to a circuit for confirming the contents of variables in a high-level language.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional in-circuit emulator includes an emulator microcomputer (microcomputer) 1, an address bus information extraction circuit 15 for extracting address bus information, and a storage address of a designated variable. And the comparison circuit 4 for comparing the address / bus information of the address / bus information extraction circuit 15 with the storage address of the designated variable storage address storage circuit 16, and the comparison circuit 4 A variable content recording circuit 5 for recording the content of the variable in the case of performing the operation, a variable content comparison circuit 6 for storing and comparing conditions for comparison with the variable content of the variable content recording circuit 5, and an emulation of the condition result of the variable content comparison circuit 6. Emulation microcomputer program execution control circuit 7 which is determined to be part of the program execution control conditions of microcomputer 1, and variable content ratio And a emulating microcomputer relation information recording circuit 8 which records as one of information relating to emulate microcomputer 1 by entering the conditions result in the circuit 6.

[0003]

In a high-level language, a program creator rarely assigns variables directly to a memory as in an assembler language, and variables are assigned to a memory at the time of compilation or program execution. In particular, when a variable is assigned to a memory at the time of executing a program, the memory address of the variable is determined according to the contents executed by the program. Therefore, the memory address could not be specified before the program was executed. For this purpose, a conventional in-circuit emulator can be used by stopping the program and immediately executing the program by taking the memory address information immediately after the process of specifying only the variable to be examined to a specific address or specifying the memory address of the variable. Was compatible. In this case, any check of the algorithm has a problem in assurance that the program is different from the final product and a problem in that a difference in execution time occurs.

If the number of bits constituting a variable used in a high-level language exceeds the number that can be handled at a time by a microcomputer, even a single instruction in a high-level language becomes a plurality of instructions in a compiled machine language, and is stored in a memory. Variables to be assigned also span multiple addresses. Even if the memory address of this variable is specified, if a single variable is used for multiple memories, the condition is actually satisfied while processing multiple memories using a conventional in-circuit emulator. However, the problem that the condition for confirming the variable is satisfied has occurred.

SUMMARY OF THE INVENTION An object of the present invention is to provide an in-circuit emulator which solves the above-mentioned problems and which prevents a program from differing from a final product, does not cause a difference in execution time, and does not erroneously satisfy a variable checking condition. To provide.

[0006]

According to the present invention, there is provided an in-circuit emulator comprising: a program counter of an emulating microcomputer; and a list of specified variables used in a program, which indicates where the specified variable is used in the program. A table storage circuit, a comparison circuit for comparing whether the specified variable of the specified variable program use list storage circuit matches the program address in which the program is written, and a variable for recording the content of the variable when the comparison circuit matches the program address A content recording circuit,
A variable content comparing circuit in which a condition to be compared with the variable content of the variable content recording circuit is stored and compared; and an emulator for judging a program execution control of a microcomputer for emulating the condition result of the variable content comparing circuit as a part of the condition. And an emulation microcomputer-related information recording circuit for inputting a condition result of the variable content comparison circuit and recording as one of information relating to the emulation microcomputer. I do.

[0007]

FIG. 1 is a block diagram showing an in-circuit emulator according to a first embodiment of the present invention. In FIG. 1, the present embodiment does not include the conventional extraction circuit 15, and uses a program counter 2 in the emulation microcomputer 1.

As a method of extracting the contents of the variables, a program counter 2 of the emulating microcomputer 1 and a specified variable program use list storing the user addresses of the variables to be examined in the program are stored. There is a comparison circuit 4 that compares the contents of the circuit 3 with the contents of the circuit 3. Each time the program executes an instruction including a designated variable, the contents of the variable are recorded in the variable content recording circuit 5, which is the condition of the emulation microcomputer / program execution control circuit 7 and the emulation microcomputer related information recording circuit. Whether or not the variable content comparison circuit 6
It is done in.

FIG. 2 is a block diagram showing an in-circuit emulator according to a second embodiment of the present invention. In FIG. 2, this embodiment corresponds to a case where the number of constituent bits of a variable used in a high-level language exceeds the number of bits that can be handled by the microcomputer at one time, and designates the program counter 2 of the emulating microcomputer 1. Variable processing head comparison circuit 10
, And the tail position comparison circuit 12 after the designated variable processing. This is performed by the specified variable processing head location program use list storage circuit 9 and the specified variable tail location program use list storage circuit 11 indicating the beginning and end of the processing of the variable to be checked.

When the processing of the designated variable is started, the contents are recorded in the variable (multiple memory configuration) contents recording circuit 13, and when the processing of the designated variable ends, the recording of the contents of the variables ends. The content of this variable is used by the variable (multiple memory configuration) content comparison circuit 14 as a judgment condition of the emulation microcomputer program execution control circuit 7 and the emulation microcomputer related information recording circuit 8.

This embodiment has storage circuits 9 and 11 and comparison circuits 10 and 12, which are twice as many as those in FIG.

[0012]

As described above, according to the present invention, even when a variable is allocated to the memory at the time of executing the program, the contents of the variable are recorded, the program execution control of the emulation microcomputer and the emulation microcomputer-related information are performed. In particular, as shown in FIG. 2, the number of configuration bits of a variable used in a high-level language can be obtained by using a plurality of memories as a storage circuit and a comparison circuit in a specified variable program as shown in FIG. Has an effect that the case where the number of bits which can be handled by the microcomputer at a time is exceeded is also taken.

[Brief description of the drawings]

FIG. 1 is a block diagram of an in-circuit emulator according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a second embodiment of the present invention.

FIG. 3 is a block diagram of a conventional in-circuit emulator.

[Explanation of symbols]

1 Emulator microcomputer 2 Program counter 3 Specified variable program use list storage circuit 4 Comparison circuit 5 Variable content recording circuit 6 Variable content comparison circuit 7 Emulation microcomputer / program execution control circuit 8 Emulation microcomputer related information recording Circuit 9 Specified variable processing head location program use list storage circuit 10 Specified variable processing head location comparison circuit 11 Specified variable processing tail location program usage list storage circuit 12 Specified variable processing tail location comparison circuit 13 Variable (multiple memory configuration) Content recording circuit 14 Variable (multiple memory configuration) content comparison circuit 15 Address / bus information extraction circuit 16 Specified variable storage address storage circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06F 11/22-11/34 G06F 9/06-9/06 550

Claims (2)

(57) [Claims] 1. An emulation microcomputer program
A counter, a designated variable program use list storage circuit indicating where the designated variable is used in the program, and the program counter is written with the designated variable of the designated variable program use list storage circuit. A comparison circuit that compares whether the program address matches the program address, a variable content recording circuit that records the variable content when the comparison circuit matches, and a condition for comparison with the variable content of the variable content recording circuit. A variable content comparison circuit, an emulation microcomputer program execution control circuit for judging the condition result of the variable content comparison circuit as a part of the program execution control of the emulation microcomputer, and a condition of the variable content comparison circuit. For emulation which inputs the result and records it as one of the information related to the emulation microcomputer In-circuit emulator, characterized in that it comprises a icon relationship information recording circuit. 2. The in-circuit circuit according to claim 1, wherein when the variable exceeds the number of bits that can be handled by the microcomputer at one time, the designated variable processing is divided into a head part and a tail part, and each of them is passed through a comparison circuit. ·emulator.