JP2701774B2 - Emulation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emulation device, and more particularly, to an emulation device for developing a program such as a target system and hardware.

[0002]

2. Description of the Related Art Conventionally, an emulation device, for example, an in-circuit emulator, is used when developing and debugging a program and hardware of a target system and the like, and its configuration generally controls the entire emulation device. It comprises a control microcomputer, an emulation device for interfacing with a target system, a control circuit for controlling the emulation state, a ROM and a RAM, and the like. In particular, it is important to stop the operation of the program during debugging, that is, to break the program and check whether the control microcomputer is in an expected state.

Such an emulation device is connected to an input / output device such as a personal computer, and outputs a break signal from a control circuit to a control microcomputer or an emulation device when the above-described break condition is satisfied during an emulation operation. Therefore, the emulation device stops the emulation operation and maintains the terminal state and the value of the internal register. Also, the control microcomputer receives the terminal state and register value from the emulation device stopped by this break signal,
It is displayed on the CRT of the input / output device. Thereafter, when a re-execution instruction is issued from the input / output device, the emulation device controls the re-execution from the stopped state.

The above-mentioned specific input / output mode and output level setting method of the terminal are described in, for example,
This is known from Japanese Patent Application Laid-Open No. 656 or Japanese Patent Application Laid-Open No. 63-126038.

[0005]

In the above-mentioned conventional emulation apparatus, the emulation device at the time of a break transfers its state to the CRT and maintains the state in the device. There is a drawback in that the port may be deteriorated or destroyed, and the target system connected to the emulation device may be destroyed.

For example, in order to turn on a light emitting diode or a fluorescent display tube of an input / output device, H / L is used as a port output.
Must be output. However, if a break occurs during these lightings, the current remains in a flowing state, which may lead to port destruction or the like.

In general, an emulation device is a device necessary for making an incomplete program into a complete program by making full use of the functions of the device. Moreover,
During debugging of this program, it is necessary to break the operation of the program and check whether or not the control microcomputer is in an expected state. However, there is a case that it is impossible to stop (break) in consideration of the values of the terminals and the internal register in the emulation device, and the terminal state in which the current continues to flow as described above may occur.

Further, according to the above two documents, since the port state can be arbitrarily specified by a program,
It prevents the current from flowing constantly. However,
In the case of an emulation device, it is necessary to re-execute in the same state as when the emulation device has stopped.
However, in the above-mentioned two known examples, since the re-execution is performed in a state different from the stop state, the expected operation is different,
The role of the emulation device cannot be fulfilled.

An object of the present invention is to provide an emulation apparatus which can prevent the emulation device and the target system from being destroyed and deteriorated and can execute the emulation device again from the same state as at the time of the break.

[0010]

An emulation device according to the present invention comprises: an external interface circuit connected to an input / output device; an emulation device connected to a target system; and an emulation device for monitoring the emulation device. A control circuit for sending a break signal to the emulation device based on a break command; a debugging program input via the external interface circuit; a terminal state at the time of the break of the emulation device; and a value of an internal register. And a RAM that saves the state of the emulation device, monitors the break command input via the external interface circuit, and sets break conditions for the control circuit. While performing, and a control microcomputer which monitors the whole.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram for explaining the use environment of the emulation device of the present invention. As shown in FIG. 1, the emulation device 2 is connected to an input / output device 1 such as a personal computer for operating the emulation device 2 and a target system 3 for debugging via a cable. Control software for controlling the emulation device 2 is recorded in the control software FD4, and is mounted on the input / output device 1 and executed. In other words, after the control software is started by the input / output device 1, various commands are sequentially executed to complete the unfinished program and the target system 3.

FIG. 2 is a block diagram of an emulation device for explaining an embodiment of the present invention. As shown in FIG. 2, the emulation device 2 includes, as circuits for external connection, an external interface circuit 10 connected to the input / output device 1 via a cable, and an emulation device connected to the target system 3 via a cable. And a device 8. A ROM 6 for storing a program and a RAM 7 for storing a program being executed, status data at the time of a break, and save data, etc.
A control circuit 5 for monitoring the contents being executed by the emulation device 8 and outputting a break signal 14 at the time of a program break; a control microcomputer 9 for controlling the entire emulation device 2; Bus 11, data bus 12, and control signal bus 1 for transferring data and various data and control signals.
3 is provided.

In the emulation device 2, the control microcomputer 9 interprets a command transferred from the input / output device 1 by using a built-in program in the ROM 6 and control software from the control software FD4 input through the external interface circuit 10. , The emulation device 8 and the control circuit 5 as well as the entire emulation device 2 are controlled. The control microcomputer 9 transfers various information from the input / output device 1 to the RAM 7 via the external interface circuit 10 and processes the information. For example, the terminal states of the input / output registers and output buffers of the ports in the emulation device 8 at the time of the break and the values of the internal registers can be registered in the RAM 7 in advance. At the time of the break, these terminal states and the values of the internal registers are saved. The terminal state and the internal register value which are registered later can be set, and processing for returning to the saved terminal state and the internal register value at the time of re-execution is performed. The emulation device 8 drives the target system 3 based on the program loaded from the input / output device 1 to the RAM 7, and debugs the program and hardware.

On the other hand, the control circuit 5 monitors the contents being executed by the emulation device 8, and when a break command is received from the input / output device 1, the control microcomputer 9 sets a break condition in the control circuit 5.
The control circuit 5 issues a break signal 14 to the control microcomputer 9 and the emulation device 8 when the condition is satisfied. The emulation device 8 that has received the break signal 14 normally stops operating immediately and enters a standby (break) state while maintaining the state. However, when the state at the time of the break is initialized, the emulation device 8 is stopped. Is saved in the RAM 7. When the emulation device 8 is set to the re-execution state from the break state setting, the break state is read from the RAM 7.

Hereinafter, the initial setting by the control software and the operation of the emulation device 2 at the time of a break will be described.
Each will be described in detail with reference to FIGS.

FIG. 3 is a flow chart of the state setting at the time of the break of the control software in FIG. As shown in FIG. 3, in the state setting at the time of a break in the control software, an initial setting value of an operating environment relating to the emulation device 8 of the emulation device 2 and the target system 3 is input in step S1. Then, step S2
It is determined whether or not to set the state at the time of the break.
Here, if there is no need to set the state at the time of the break, the end processing is performed as in step S6. In this case, the operation becomes the same as the conventional operation.

On the other hand, as a result of the determination in step S2, if it is necessary to set a state at the time of a break, that is, if it is necessary to prevent terminal deterioration or other destruction of a circuit at the time of a break,
As shown in step S3, the input / output setting of the terminal, for example, setting whether the terminal is used as an input terminal or an output terminal is performed. At this time, if the terminal is an output terminal, the output level of the output terminal is set so that the output level is set to H level or L level. Of course, such information is stored in the RAM 7
This is for specifying the information to be saved. In step S3, when pulse output from a timer or the like is required continuously in addition to the above, an internal register value such as prohibiting stop of the timer operation is set. In addition, the evacuation information is selected at any time.

Further, in step S4, step S3
Is transferred from the input / output device 1 to the emulation device 2 and the storage in the RAM 7 is instructed. In short, the content set in step S3 is transferred from the input / output device 1 to the emulation device 2, and the control microcomputer 9
Is stored on the RAM 7. Through these steps, the input of the initial setting values of the operating environment of the emulation device 2 is completed as shown in step S5.

FIG. 4 is a flowchart showing the operation of the emulation device shown in FIG. 2 at the time of a break. As shown in FIG.
In step S11, the debugging work in the emulation device 2 is started. Next, as shown in step S12, when a break condition is satisfied during debugging work of the emulation device 2, the control circuit 5 issues a break signal 14. Thus, the emulation device 8 stops operating and maintains the internal state.

Further, the control microcomputer 9 executes step S13.
At the same time, the internal state of the emulation device 8, that is, the state of terminals and internal registers, is saved in the RAM 7, and at the same time, the internal state is transferred to the input / output device 1 and displayed on a CRT or the like. Here, the break processing is completed, and the emulation device 8 and the target system 3 enter the break state.

Next, in re-execution of debugging, first, in step S14, the emulation device 8 is executed.
Change the internal state of. That is, the control microcomputer 9 sets the terminal of the emulation device 8 and the internal register value according to the initial settings stored in the RAM 7 in step S4 of FIG. Next, in step S15, the debug of the emulation device 8 is re-executed. At this time, the control microcomputer 9 determines in step S13 that the RAM 7
This is executed by resetting the emulation device 8 according to the internal state at the time of the break that was saved. Thus, the debugging work of step S16 ends. In this way, by saving the terminal and internal register value of the emulation device 8 at the time of a break, deterioration and destruction of the terminal and the internal register can be prevented, the influence on the target system 3 is eliminated, and even when re-executing. It can be executed from the same state as at the time of the break.

In short, when the state at the time of the break is set in the initial setting, the control circuit 5 monitors the execution contents of the emulation device 8 and the control microcomputer 9 monitors the break command from the input / output device 1. I have. At this time, the control microcomputer 9 sets a break condition for the control circuit 5. Therefore,
When the control circuit 5 monitors the emulation device 8 and satisfies the break condition, the break signal 1
4 to the emulation device 8. Thereby, the emulation device 8 stores the state in the RAM 7
After being evacuated and transferred to the CRT of the input / output device 1, the operation is stopped and a break state is set. Further, the break signal 14 is transmitted from the control circuit 5 to the control microcomputer 9.
Control microcomputer 9 stops monitoring the break command until a re-execution command arrives. Thereafter, when the control microcomputer 9 receives the re-execution command, it resets the state of the emulation device 8 again according to the state saved in the RAM 7.

[0023]

As described above, the emulation device according to the present invention comprises a control circuit for sending a break signal to an emulation device in response to a break instruction from an input / output device, an initial setting information, and an emulation device at the time of a break. R to save the state of
By providing an AM and a control microcomputer for performing overall control, a debugging operation environment of the emulation device at the time of a break, that is, a terminal and an internal register value are registered in advance, and at the time of a break, the RAM is set in the RAM according to the registered contents. When re-executed, it can be returned to the break state, preventing destruction or deterioration of the emulation device or target system, and re-executing the same state as at the time of the break despite changing the pin state There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a system diagram illustrating an environment in which an emulation device according to the present invention is used.

FIG. 2 is a block diagram of an emulation device for explaining an embodiment of the present invention.

FIG. 3 is a state setting flow chart at the time of a break of control software in FIG. 1;

FIG. 4 is an operation flow chart at the time of a break of the emulation device shown in FIG. 2;

[Explanation of symbols]

 Reference Signs List 1 input / output device 2 emulation device 3 target system 4 control software FD 5 control circuit 6 ROM 7 RAM 8 emulation device 9 control microcomputer 10 external interface circuit 11 to 13 bus

Claims (1)

(57) [Claims] 1. An external interface circuit connected to an input / output device, an emulation device connected to a target system, and a break to the emulation device based on a break command from the input / output device monitoring the emulation device. A control circuit for transmitting a signal, a debugging program input through the external interface circuit, and a terminal state at the time of a break of the emulation device and a value of an internal register are registered in advance. RAM to save
And a control microcomputer that monitors the break command input via the external interface circuit, sets break conditions for the control circuit, and monitors the entirety.