JPH0426138B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a data processing technology, and relates to a technology that is effective when used in a device such as an emulator that emulates a microprocessor.

[Background Art] When developing or debugging software for a microcomputer system developed by a user, an apparatus as shown in FIG. 2 is sometimes used. That is, microprocessor system (user system) 1
An adaptive system evaluator (hereinafter referred to as ASE) is connected via a connector 3 to an IC socket 2 for a microprocessor (hereinafter referred to as MPU) provided on board 1a constituting the system. ) 4. This ASE4 is connected via cable.
It is connected to a system development device 7 called a support tool that includes a CRT display 5, floppy disk devices 6a and 6b, and the like.

In the above system, a source program written in a language such as an assembler or compiler that is input from the keyboard of the CRT display 5 is
First, it is written to the floppy disk 6a, translated into machine language by the MPU in the system development device 7, and written to the floppy disk 6b in the form of an object program. The program written to the floppy disk 6b is transferred to the user system 1 by the MPU in the ASE4.
The data is transferred to RAM (random access memory) 8, etc., and written.

When the connector 3 is pulled out from the IC socket 2 and the system's MPU 9 is inserted, the user program written in the RAM 8 etc. is normally executed by the MPU 9. Now, MPU in ASE4
(same type as MPU9) allows user programs to be debugged while emulation is being performed.

In this case, you can control the CTR display 5, floppy disk devices 6a, 6b, etc.
It is possible to translate assembler and compiler languages into machine language, and furthermore, by using the MPU in ASE4, user
Run the program and edit the data obtained.
Host to display on CRT display 5
The MPU is installed in the system development device 7, and the emulator uses data obtained as a result of emulation to be stored in the system development device 7.
It is possible to provide functions that allow the MPU to process data in a format that is easy to edit. In the above system,
The MPU in ASE4 serves both emulation and data processing functions. Therefore,
The MPU in the ASE 4 is spatially divided into emulation mode and system mode for execution based on control signals output from the controller in the system development device 7.

An emulator system having the above configuration has already been disclosed in Japanese Patent Application No. 58-34565 and the like.

By the way, when debugging a user program using the above-mentioned emulator system, the program is generally cut into pieces and emulation is performed. This is detected and the execution of the program is interrupted at that point.

In the break method described above, if the signal etc. on the address bus is monitored and the program is interrupted (break) when the address matches a predetermined condition, the execution of the program is stopped as soon as the break condition such as the address is met. Ru. Therefore, the state of the system just before a break can be determined by capturing the data on the bus into a storage device called trace memory in real time, and by analyzing the contents of the trace memory after a break, the cause of a runaway program can be determined. It is possible to solve problems and debug user programs and systems.

However, rather than interrupting the program as soon as the break condition is met, it is easier to determine the cause of the runaway if the program is stopped several cycles after the break condition is met and the operating state of the system up to that point is known. This was revealed by the present inventors.

However, in conventional systems, in order to stop a program after a predetermined amount of time has passed after a break condition is satisfied, it is necessary to set a new breakpoint and continue the program, which is a tedious task. It is. Furthermore, if there is a jump instruction or the like on the way to a newly set breakpoint, there is also the inconvenience that the program cannot be interrupted immediately.

[Object of the Invention] An object of the present invention is to make it easier to determine the cause of program runaway in a data processing system such as an emulator, thereby improving the efficiency of debugging.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the Invention] Representative inventions disclosed in this application will be summarized as follows.

That is, in a data processing system such as an emulator, in addition to means for detecting the establishment of a break condition, a break generation means is provided that outputs a stop signal to the microprocessor when a predetermined period of time has elapsed after the establishment of the break condition. By doing so, it is possible to see the operating state of the system after the break condition has been met, thereby making it easier to clarify the cause of runaway, etc., and achieving the above purpose of improving the efficiency of debugging. be.

[Embodiment] FIG. 1 shows an embodiment of an emulator system according to the present invention.

In the same figure, what is indicated by the reference numeral 10 is
An emulation MPU (microprocessor) installed in the ASE (adaptive system evaluator) 4 shown in Figure 2.
This MPU 10 is composed of MPUs of the same type as the MPU 9 that constitutes the user system. And for this emulation
An in-circuit emulator is constituted by the MPU 10, a controller 11 provided in the system development device 7, a retouch circuit 12, and a break circuit 20.

The trace circuit 12 has a memory and a counter that chronologically captures input/output signals appearing on the bus while the MPU 10 executes a user program. Break circuit 20
is a register that sets the conditions for the end (breakpoint) of a series of programs to be divided and executed during debugging, and a hardware comparison between the contents of this register and the address signal on the bus, etc. A break condition judgment circuit 21 detects whether or not a match has occurred, a counter 22 starts a counting operation in response to a match detection signal φc output from this judgment circuit 21, and a count value of this counter 22 reaches a predetermined value. Interrupts the MPU 10 above based on the timeout signal φt that is output when
MPU interrupt stop signal IRQ that stops MPU operation
and a break generation circuit 23 that generates a trace stop signal φst that stops the trace circuit 12 from receiving signals on the bus.

Although not particularly limited, the above MPU interrupt stop signal
The IRQ is formed into a signal that can be used to interrupt the MPU 10 using software. This makes it possible to open all the interrupt control terminals provided in the MPU 10 to the user.

The controller 11 is also connected to the host MPU 15 that controls the system development device 7 via the bus 14, and when a command such as execution of a user program is received from the keyboard of the CRT display, it is checked whether the command is for ASE or not. It is determined whether or not the command is available, and the command is supplied to the MPU 10. When the MPU 10 receives this command, it outputs an appropriate address signal to switch the space, that is, from system mode to user mode.
Switch to emulation mode to execute the program.

The count value of the counter 22 can be arbitrarily set in advance by the controller 11, and is output from the MPU 10, for example. An appropriate delay time is obtained by counting the system clock E which defines memory cycles.

Next, the operation when debugging a user program using the emulator system will be described.

If a loop in the user program you are trying to debug contains a bug, the program may break out of the loop and jump somewhere else. Therefore, when debugging, the program is divided and emulation is performed. Therefore, it is necessary to set conditions (breakpoints) to interrupt the program.

The above-mentioned breakpoints may target signals output from the MPU 10 onto the address bus, or may target signals output onto the data bus.

In this embodiment, the host MPU 1 is loaded before executing the user program by emulation.
5, the controller 11 sets the breakpoint given from the keyboard or the like in a register in the break condition determination circuit 21. Similarly, the count value of the counter 22 is also set by the controller 11 before starting emulation.

Then, the MPU 10 starts emulation in response to a command from the host MPU 15.
At the same time, the trace circuit 12 operates an internal counter in response to a control signal from the controller 11, and sequentially captures the signals appearing on the bus at that time into the internal memory.

In addition, the break condition determination circuit 21 is also
It monitors a predetermined signal on the bus supplied from the bus, and successively compares it with breakpoints set in internal registers.

In this way, when emulation is performed without activating the trace circuit 12 and the break condition determination circuit 21, if it is determined that the signal on the bus matches the break condition and the break point has been passed, the break occurs. A match signal φc is output from the condition determination circuit 21. This signal causes the counter 22 to start counting, and when the counted value reaches the set value after a predetermined period of time, a timeout signal φt is output.

Then, upon receiving this timeout signal φt,
The break generation circuit 23 issues a software interrupt to stop the operation of the MPU 10, and also sends a trace stop signal φst to the trace circuit 12 to stop taking in data on the bus and stop the internal counter.

As a result, the data in the memory in the trace circuit 12 is read out while referring to the counter, and after being subjected to appropriate processing, it is sent to the host MPU 15 side.
After the host MPU 15 edits this, it is displayed on the CRT display (see FIG. 2), so that the state of the bus before the MPU 10 stops can be known. With this, even if the MPU 10 goes out of control immediately after passing a breakpoint, the state can be known, and the cause of the runaway can be easily determined.

Furthermore, by changing the set value of the counter 22, the delay time from passing the breakpoint to stopping the MPU can be arbitrarily changed, allowing efficient debugging.

Furthermore, it goes without saying that if the set value of the counter 22 is set to zero, the MPU can be stopped when a breakpoint is passed, similar to conventional emulator systems.

However, instead of making the count value of the counter 22 variable as in the above embodiment, it is fixed and the count value is always set after a certain period of time after passing the breakpoint.
The MPU may be stopped.

Note that since there is a limit to the capacity of the memory in the trace circuit 12, in the above embodiment,
When the memory overflows, it returns to the starting address and writes new data over the data that has already been taken in. As a result, even if it takes a long time to reach a breakpoint, you can always know the state of the bus just before the MPU stops.

Also, when debugging a program, you may end up repeating a certain loop dozens or hundreds of times before breaking out of the loop and jumping to another location. Therefore, in order to detect such debugging, the break condition determination circuit 21 is provided with a counter that counts the number of times the breakpoint has been passed and a register that sets the number of times the breakpoint has been passed. The MPU may be operated and the operation of the MPU may be stopped after a certain delay time.

In addition, as mentioned above, the memory in the trace circuit 12 has a limit on the amount of data that can be loaded into it, so when a certain loop of a program is repeatedly executed, a series of programs is run and the bus is In some cases, it may be desired to capture the signal into the memory in the trace circuit. Therefore, in order to be able to detect when a certain point has been passed and start tracing from there, we need to create a register to set the specified point (trigger point) and detect whether or not the trigger point has been passed. A circuit for forming a trace start signal may be provided.

[Effect] In a data processing system such as an emulator, in addition to means for detecting the establishment of a break condition, there is also a means for generating a break that outputs a stop signal to the microprocessor when a predetermined period of time has elapsed after the establishment of the break condition. This feature allows you to see the operating status of the system after the break condition is met, making it easier to identify the cause of runaway, and also to know the passing status of coverage paths, etc. This has the effect of improving the efficiency of debugging.

Although the invention made by the present inventor has been specifically explained based on Examples above, the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Needless to say. For example, in the above embodiment, the break generation circuit 23 is configured to generate a signal that can interrupt the MPU 10 by software and stop the operation. It is also possible to configure the terminal to stop by applying an appropriate signal.

[Field of Application] In the above explanation, the invention made by the present inventor was mainly applied to the emulator system, which is the field of application that formed the background of the invention, but it is not limited to this, and applies to the application of the invention to the emulator system. In a system such as a track analyzer, it can be used when it is desired to detect the occurrence of a specific event and start or stop some operation.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram showing an embodiment of the main part of an emulator system to which the present invention is applied;
FIG. 2 is a schematic configuration diagram showing an example of the overall configuration of an emulator system to which the present invention is applied. 1... User system, 2... IC socket, 3... Connector, 4... ASE (Adaptive System Evaluator), 5... CRT display, 6a, 6b... Floppy disk device, 7... System Development equipment, 8...RAM,
9...MPU (microprocessor), 10...MPU for emulation, 11...controller,
12...Storage means (trace circuit), 14...Bus, 15...Host MPU, 20...Break circuit, 21...Detection means (break condition determination circuit).

Claims (1)

[Scope of Claims] 1. A method for detecting the occurrence of a certain event in a data processing system equipped with the same type of microprocessor as the microprocessor of the target system and capable of emulating that system. It has a register in which data is stored, a means for detecting the occurrence of the above event by comparing the contents of the register with a signal on the bus, and a means for detecting the occurrence of the above-mentioned event after a predetermined time based on the detection signal from the detecting means. Data processing characterized by comprising: break generation means for outputting a stop signal to the processor; and storage means for successively capturing and holding the state of the bus until the microprocessor is stopped by the stop signal. system. 2. The break generating means has a counter whose set value can be arbitrarily changed, and the counter is operated based on the detection signal from the detecting means,
2. The data processing system according to claim 1, wherein the data processing system is configured to output a stop signal after a predetermined time.