JPH02242344A - In-circuit emulator device - Google Patents

Abstract

PURPOSE:To improve the processing capacity by combining a circuit for storing a state of various signals of a central processing unit in accordance with an execution timing of the central processing unit, and a circuit for storing simultaneously a head address, as well of a storage device in which an instruction executed by the central processing unit is placed. CONSTITUTION:Various signals from a central processing unit 1 are supplied to a storage command timing signal generating circuit 2 and a trace storage circuit 3. Also, a head address of an instruction which is being executed of the central processing unit 1 outputted from the central processing unit 1 is supplied to a program counter trace storage circuit 4, and stored. Information stored in the trace storage circuit 3 and the program counter trace storage circuit 4 is compared and analyzed by a trace result analytic program 5 at the time point when it becomes necessary, and a result of its analysis is outputted to an output device 7 by a trace result display program 6.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an in-circuit emulator device that is capable of storing various signals of a central processing unit that executes a program while the central processing unit is executing the program. It is.

[Prior Art] In recent years, many types of central processing units have come into existence, but when designing electronic devices using these central processing units, it is important to know how to develop software and hardware. As an example, in-circuit emulator devices are commonly used.

An important function of this Inzerkit emulator device is that the central processing unit memorizes the process of the program being executed step by step, and the memorized contents can be made available to the interviewer at any necessary time. There is a trace function that can be displayed in .

In a general in-circuit emulator device, various signals input from an external circuit to the central processing unit and various signals output from the central processing unit to the external circuit are transmitted at each operation reference timing of the central processing unit. It has a memory function. The various signal states of the central processing unit that have been memorized are displayed as they are without any modification.
It is extremely difficult to understand the process by which a program is executed. Therefore, general in-circuit emulator devices classify and analyze the stored various signal states of the central processing unit according to the order in which they were processed by the central processing unit and the type of signal. A program is available that converts the instructions into assembler instructions and, if the instruction is executed, converts it to what kind of data was processed and where it was executed.

[Problems to be Solved by the Invention] Many recent central processing units have increased the operating frequency of the central processing unit in order to increase processing capacity, while also increasing the amount of information that the central processing unit can handle at one time. Cache instructions and data inside the central processing unit for the purpose of increasing processing width, parallel processing by pipelines for fetching, parsing, and execution of instructions to be processed, and preventing reduction in processing performance when external storage devices are slow. Many methods are being used to increase processing power, such as motsu. However, on the other hand, the order in which programs are executed in the central processing unit may be changed, or instructions taken by the central processing unit may not be executed. Analyzing behavior has become extremely difficult.

Therefore, in the present invention, such instructions are taken in, analyzed,
Although the processing order of execution is not constant and it is not known when the beginning of the instruction is taken in, it has a function in which the beginning address of the instruction being executed is output as a signal from the central processing unit. In addition to storing various signals of the central processing unit (an example of which is National Semiconductor's Series 32000 family) when the central processing unit is executing a program, it also stores the beginning of the instruction being executed. The purpose of the present invention is to provide an in-circuit emulator device that simultaneously stores addresses, references and compares these two storage results, analyzes the program execution process, and displays the converted results in an easy-to-understand format. .

[Means for Solving the Problems] In order to achieve the above object, an in-circuit emulator device according to the present invention detects a state in which data is taken into the central processing unit or data is output from the central processing unit. , a circuit that generates a storage command timing signal for various signals of the central processing unit, and a trace storage circuit that stores various signals of the central processing unit in conjunction with the storage command timing signal from the storage command timing signal generation circuit;
It has a program counter trace memory/failure circuit that stores the starting address of the instruction being executed by the central processing unit in conjunction with the timing at which the starting address of the instruction being executed by the central processing unit is output from the central processing unit. It is characterized by

According to another feature of the in-circuit emulator device according to the present invention, in addition to the above configuration, a trace result analysis that compares and analyzes information stored in the trace storage circuit and the program counter trace storage circuit is provided. program, and a trace result display program that displays the analysis results of the trace result analysis program.

[Function] In the in-circuit emulator device of the present invention configured as described above, the states of various signals of the central processing unit are stored, and at the same time, the starting address of the memory where the instruction being executed by the central processing unit is located is stored. are stored, and the results of both storages are referenced and compared, so that the complex operating processes of the central processing unit can be converted and displayed in a simple format that can be easily understood by the operator.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a block diagram of the configuration of the in-circuit emulator device of the present invention, in which 1 is a central processing unit prepared by the in-circuit emulator device that operates in place of the central processing unit of the target system to be developed. Various signals from this replacement central processing unit 1 are command timing signals that detect the state in which the central processing unit 1 performs data input/output with the outside, and store various signals of the central processing unit 1. The signals are supplied to a storage command timing signal generation circuit 2 which generates the signals, and are also supplied to a trace storage circuit 3 which stores these various signals.

Further, the starting address of the instruction being executed by the central processing unit outputted from the central processing unit 1 is supplied to the program counter trace storage circuit 4 and stored therein. The storage command timing signal generation circuit 2 analyzes various signals of the central processing unit 1, and based on the operating status of the central processing unit, outputs various signals and
A timing signal is generated to store the start address of the instruction being executed by the central processing unit. In synchronization with the timing signal generated by the storage command timing signal generation circuit 2,
The trace storage circuit 3 and the program counter trace storage circuit 4 are each configured to sequentially store signals to be stored.

The information stored in the trace storage circuit 3 and the program counter trace storage circuit 4 is compared and analyzed by a trace result analysis program 5 prepared inside the in-circuit emulator device when necessary, and the analysis results are is output to the output device 7 by the trace result display program 6.

Next, using a simple program example, a description will be given of how the process of executing a program by the central processing unit is displayed when the present invention is used and when it is not used.

For example, assuming that a program as shown in FIG. 2 is executed by a central processing unit, the information stored in a trace storage circuit implemented in a conventional manner would be as shown in FIG.

If the information stored in this trace storage circuit is analyzed and displayed without comparing it with the starting address of the instruction being executed by the central processing unit, as in the past, it will look like Figure 6, which is actually Even programs that are not being executed by the central processing unit are displayed, and as a result, it is very difficult to confirm whether the program shown in FIG. 2 is being executed.

Here, when the information stored in the program counter trace storage circuit 4 is combined with the information stored in the trace storage circuit 3, information as shown in FIG. 4 is obtained. By analyzing the information shown in FIG. 4 and extracting and displaying only the part actually executed by the central processing unit 1, a display result as shown in FIG. 5 can be obtained, and the program shown in FIG. This allows you to easily check what is being executed.

[Effects of the Invention] As explained above, in the in-circuit emulator device according to the present invention, the states of various signals of the central processing unit are adjusted to the execution timing of the central processing unit during the process in which the central processing unit executes a program. By combining a circuit that simultaneously stores the starting address of the storage device where the instruction being executed by the central processing unit is located, in addition to the circuit that stores the instructions being executed by the central processing unit, the central processing unit is now able to execute and process programs. Compared to the process that was displayed as a trace result in the same order, it is now possible to display only the necessary information more accurately about the process of program execution. The process can be easily understood.

In addition, in the conventional in-circuit emulator device, the starting address of the storage device where the instructions being executed by the central processing unit are located is not stored at the same time. It was necessary to prepare a very complicated analysis program inside the in-circuit emulator device in order to display the information in an easy-to-understand manner for emulator users. is stored, it becomes possible to easily create an analysis program inside the in-circuit emulator device to accurately display only necessary information.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an in-circuit emulator device of the present invention, FIG. 2 is a diagram showing an example of a program, FIG. The figure shows an example of the combination of the information stored in the program counter trace storage circuit and the information stored in the trace storage circuit. Figure 6 shows an example of
The figure shows an example in which information stored in a trace storage circuit is analyzed and displayed using a conventional method. In the figure, central processing unit 2: storage command timing signal generation circuit 3 Nidrace storage circuit 4 Nitrogram force countertrace storage circuit 5 Nidrace result analysis program 6; trace result display program 7: output device Figure 1 Figure 2 1000 test: movb o(ro), r
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Claims (1)

[Claims] 1. In the program execution process by the central processing unit,
In an in-circuit emulator device that is capable of storing the states of various signals of the central processing unit in accordance with the execution timing of the central processing unit, the state in which data is taken into the central processing unit or data is output from the central processing unit a circuit that detects and generates a storage command timing signal for various signals of the central processing unit; and a trace that records various signals of the central processing unit in conjunction with the storage command timing signal from the storage command timing signal generation circuit. a storage circuit; and a program counter trace storage circuit that stores the starting address of an instruction being executed by the central processing unit in synchronization with the timing at which the starting address of the instruction being executed by the central processing unit is output from the central processing unit. An in-circuit emulator device comprising: 2. During the program execution process by the central processing unit,
In an in-circuit emulator device that is capable of storing the states of various signals of the central processing unit in accordance with the execution timing of the central processing unit, the state in which data is taken into the central processing unit or data is output from the central processing unit a circuit that detects and generates a storage command timing signal for various signals of the central processing unit; and a trace that records various signals of the central processing unit in conjunction with the storage command timing signal from the storage command timing signal generation circuit. a storage circuit; a program counter trace storage circuit that stores a starting address of an instruction being executed by the central processing unit in conjunction with a timing at which the starting address of the instruction being executed by the central processing unit is output from the central processing unit; An in-circuit characterized by having a trace result analysis program that compares and analyzes information recorded in the trace storage circuit and the program counter trace storage circuit, and a trace result display program that displays the analysis results of the trace result analysis program. emulator device.