JP2000003290A - In-circuit emulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continue debug even when a target system runs away due to the generation of the abnormality of a user interrupting program when accepting user interruption in a monitor mode in an in-circuit emulator. SOLUTION: This in-circuit emulator is newly provided with an interruption control circuit 5. A break signal to be transmitted to a microprocessor 6 can be selected from among plural kinds of brake signals 104 and 105, and when a 'monitor mode' is obtained from the low level break signal 104, a user interrupting signal 107 can be accepted. When an abnormal operation is generated in the user interruption processing, the 'monitor mode' is obtained from the break signal 105 for preferentially obtaining the monitor mode, and debug can be continued. Thus, it is possible to respond to the user interrupting signal 107 of a target system 3 in a real time even in the break state, and even when any abnormal operation is generated in the user interruption processing, the debug can be continued.

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.

[0002]

2. Description of the Related Art As a conventional in-circuit emulator, for example, one disclosed in Japanese Patent Application Laid-Open No. 7-152598 is known. This in-circuit emulator includes an emulator control circuit, a microprocessor, a return instruction detecting circuit, a flag, an interrupt detecting circuit, and an OR circuit, and is connected to a host device and a target system.

Hereinafter, an example of a conventional in-circuit emulator will be described with reference to FIGS. FIG. 5 is a block diagram of an example of a conventional in-circuit emulator.

A conventional in-circuit emulator 51 is
An emulator control circuit 52, a microprocessor 53,
Return instruction detection circuit 61, flag 62, interrupt detection circuit
63 and a logical sum (OR) circuit 64, and are connected to the host device 1 and the target system 3.

The microprocessor 53 includes a main bus 154
And has the following function in addition to the function of acting on behalf of the processor of the target system 3. 1. Privilege break that takes precedence over all dedicated user interrupts required when transitioning from “user mode” executing a user program to “monitor mode” executing a program that implements the function of the in-circuit emulator The function of inputting the signal 153 from the OR circuit 64. 2. User interrupt signal 15 from target system 3
Ability to enter 5.

The emulator control circuit 52 is connected to a host control bus 151 and further connected to a main bus 154, and has at least the following functions. 1. A function for monitoring the operation of the target system 3. 2. Function for debugging the user program of the target system 3. 3. A function of receiving an operation instruction from the host device 1 and a function of transmitting an operation result to the host device 1 (command / data interface function). 4. A function of outputting a break signal 152 for the microprocessor 53 to transition to the “monitor mode” to the OR circuit 64.

The return instruction detecting circuit 61 is connected to the main bus 15
4, a circuit for detecting a return instruction from the user interrupt operation of the microprocessor 53. When the return instruction appears on the main bus 154, a break signal is sent to the microprocessor 53 via the OR circuit 64. (Return command detection signal) 156 is output.

The flag 62 is a memory connected to the main bus 154 for storing the procedure through which the transition to the "monitor mode" is made. The write / read operation from the microprocessor 53 is performed by the flag 62. It is possible.

The interrupt detection circuit 63 is a circuit for detecting a user's interrupt signal 155 output from the target system 3 and outputting it to the host device 1. The host device 1 is an input / output device of the in-circuit emulator 51. The host device 1 has a function of giving an operation instruction to the emulator control circuit 52 and a function of receiving an operation result for the emulator control circuit 52. Control bus
Input / output via 151.

The target system 3 is a general computer system having a memory device and an I / O for storing program data to be debugged in the in-circuit emulator 51, and has a user interrupt required for real-time control. It has a function of outputting a signal 155.

Next, the operation of the conventional in-circuit emulator 51 having the above configuration will be described. When a break request is notified from the host device 1 to the emulator control circuit 52, or when the emulator control circuit 52 detects an event of transition to the “monitor mode” while monitoring the operation of the target system 3, the emulator control circuit 52 performs OR operation. A break signal 152 is transmitted to the microprocessor 53 via the circuit 64.

Then, the microprocessor 53 sets the flag
62 is checked, the flag 62 is set as a transition from the normal "user mode" to the "monitor mode", and the return address to the program space of the target system 3 is saved. Then, the microprocessor 53 executes command processing (command processing for realizing the in-circuit emulator function) input from the host device 1 via the emulator control circuit 52.

When the user interrupt signal 155 is output from the target system 3 and the signal 157 output from the interrupt detection circuit 63 becomes active, the host device 1 executes the interrupt processing in the program space of the target system 3 corresponding to the user interrupt. The microprocessor forcibly branches the command via the emulator control circuit 52.
53, and the microprocessor 53 executes an interrupt process in the target system space. When this interrupt processing is completed and the end of the interrupt processing (return instruction) is detected by the return instruction detection circuit 61, a break signal 156 is output and input to the microprocessor 53 as a break signal 153 via the OR circuit 64. You. However, the break signal
When 153 is active, the microprocessor 53 executes the monitor mode processing from the beginning. At this time, since the flag 62 is set, the return address for returning to the user mode is not saved.

Thereafter, the microprocessor 53 repeats the processing from the command processing for realizing the emulator function, but from the "monitor mode" to the "user mode".
Is notified from the host device 1 via the emulator control circuit 52, the flag 62 is reset, a return address for returning to the "user mode" is read, and the process branches to that address.

With such a configuration, it is possible to accept a user interrupt even in the monitor mode for the target system 3 that requires real-time control such as motor control, and the runaway of the target system 3 due to the fact that the user interrupt is not processed. It is possible to prevent.

A series of operations in the conventional "monitor mode" will be described with reference to FIG. (Step-301) When the monitor mode is entered, command processing for realizing the function of the in-circuit emulator is performed. (Step-302) Next, it is determined whether or not there is a user interrupt from the target system 3. If there is no user interrupt, the process returns to step -301 to repeat the processing from the command processing. (Step-303) If it is determined in step-302 that there is a user interrupt, the process proceeds to a user interrupt process. When the user interrupt process ends, the process returns to step -301 and repeats from the command process again.

[0017]

However, in such a conventional in-circuit emulator 51, it is possible to accept a user interrupt during the "monitor mode". Breaks out, privilege break signal
Even if the system temporarily returns to the “monitor mode” due to 153, it is impossible to continue debugging because the process is forcibly shifted to a defective user interrupt process again.

It is an object of the present invention to allow such an in-circuit emulator to accept a user interrupt during the monitor mode and continue debugging even if the user interrupt program is defective and the target system runs away.

[0019]

According to an in-circuit emulator of the present invention, at least a break signal for transition to a monitor mode and an emulator control circuit for generating a selection signal therefor, and a break signal from the emulator control circuit are received. An interrupt control circuit that selects and outputs one break signal according to a selection signal from the emulator control circuit from among a plurality of types of break signals for transitioning to the monitor mode, and an interrupt control circuit that receives the break signal from the interrupt control circuit When the break signal is a signal that allows a user interrupt, a user interrupt from the target system is received during the monitor mode, and when the break signal received from the interrupt control circuit is a signal that prioritizes the monitor mode over the user interrupt, The target system Is obtained by a configuration in which a priority microprocessor monitor mode from the user interrupt from the beam.

According to the present invention, a user interrupt is accepted during the monitor mode, and debugging can be continued even if the user interrupt program is defective and the target system runs away.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention according to claim 1 of the present invention provides an emulator control circuit for generating at least a break signal for transition to a monitor mode and a selection signal therefor, and receiving a break signal from the emulator control circuit. An interrupt control circuit for selecting and outputting one break signal from a plurality of types of break signals for transitioning to the monitor mode in accordance with a selection signal from the emulator control circuit, and receiving from the interrupt control circuit When the break signal is a signal that allows a user interrupt, a user interrupt from the target system is received during the monitor mode, and the break signal received from the interrupt control circuit is a signal that prioritizes the monitor mode over the user interrupt. , User interrupt from the target system And a microprocessor that prioritizes the monitor mode. In the monitor mode, when the break signal is a signal that allows a user interrupt, the user interrupt can be accepted. If the target system goes out of control, the break signal is set to a signal that prioritizes the monitor mode over the user interrupt, so that the command processing that realizes the function of the in-circuit emulator has priority over the user interrupt, and the defective user interrupt is not executed Therefore, there is an effect that debugging can be continued.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an in-circuit emulator according to an embodiment of the present invention.

In-circuit emulator 2 of the present invention
Are the emulator control circuit 4 and the interrupt control circuit 5
And a microprocessor 6, and are connected to the host device 1 and the target system 3.

The microprocessor 6 has a main bus 106
And has the following function in addition to the function of acting on behalf of the processor of the target system 3. 1. Multiple types of dedicated break signals 104 and 105 required when transitioning from “user mode” to “monitor mode”
The ability to enter. 2. User interrupt signal 10 from target system 3
Function to enter 7.

The emulator control circuit 4 is connected to the host control bus 101 and further connected to the main bus 106, and has at least the following functions. 1. A function for monitoring the operation of the target system 3. 2. Function for debugging the user program of the target system 3. 3. A function of receiving an operation instruction from the host device 1 and a function of transmitting an operation result to the host device 1 (command / data interface function). 4. Function for receiving a break request from the host device 1. 5. A function of outputting a break signal 102 for transitioning to the “monitor mode” to the interrupt control circuit 5. 6. A function of outputting a selection signal 103 for selecting a type of a break signal to be output in the interrupt control circuit 5;

As shown in FIG. 2, the interrupt control circuit 5 includes a selector 11, which receives a selection signal 103 from the emulator control circuit 4 and outputs a break output 102 from the emulator control circuit 4 It has a function of selecting whether to output as level break signals (a plurality of types of break signals) 104 and 105 and outputting the signals to the microprocessor 6.

The host device 1 is an input / output device of the in-circuit emulator 2, is connected to the emulator control circuit 4, and has a function of giving an operation instruction to the emulator control circuit 4 and a function of receiving an operation result for the function. have.

The target system 3 is a general computer system including a memory device and an I / O in which program data to be debugged in the in-circuit emulator 2 is stored, and a user interrupt required for real-time control. A function of outputting the signal 107 is provided.

FIG. 3 is a block diagram showing input / output of an interrupt controller in the microprocessor 6 according to the embodiment of the present invention. The interrupt controller 12 in the microprocessor receives a plurality of break signals 104 and 105, outputs an interrupt request 108 to the microcomputer core 13, and receives a user interrupt in the target system space according to the level of the break signal. It has a function to set the level.

The in-circuit emulator 2 having the above configuration
Will be described. When a transition is made from the “user mode” to the “monitor mode”, a break request is notified from the host device 1 to the emulator control circuit 4 via the host control bus 101.

When the break request is input, the emulator control circuit 4 outputs a break signal 102 to the interrupt control circuit 5. In response to this, the interrupt control circuit 5 outputs the break signal selected by the selection signal 103 from the plurality of types of break signals 104 and 105 to the microprocessor 6.

In this embodiment, the interrupt control circuit 5 receives the break signal 102 from the emulator control circuit 4 and instructs the microprocessor 6 the privileged break signal 10 which gives priority to the "monitor mode" over the user interrupt level.
A case where a low-level break signal 105 whose level is lower than the level 4 or the privilege break signal 104 is output will be described as an example.

When the microprocessor 6 receives the privileged break signal 104 or the low-level break signal 105 and transits to the “monitor mode”, the target system 3
The transition process from the general "user mode" to the "monitor mode" is performed, such as saving the return address of the user program in the space.

When a transition is made using the low-level break signal 105, the microprocessor 6 can accept a user interrupt having a higher level than the low-level break signal 105 in the target system space in addition to the conventional in-circuit emulator operation. It is possible. This allows
Even during the “monitor mode”, the user interrupt 107 can be accepted for the target system 3 requiring real-time control such as motor control.
When the transition is made using the privilege break signal 104, the "monitor mode" can be prioritized over all the user interrupts 107 in the "monitor mode" as in a general in-circuit emulator.

The case where the low-level break signal 105 causes a transition from the user mode to the monitor mode and the level of the user interrupt 107 is higher than the low-level break signal will be described below.

When the level of the user interrupt signal 107 is higher than that of the low-level break signal, the microprocessor 6 accepts the user interrupt signal 107, and when the microprocessor 6 is processing the user interrupt program, the user interrupt program is defective. Then, the target system 3 may run away.

In case of runaway, the target system 3
The emulator control circuit 4 that monitors the program selects the privileged break signal 104 and inputs it to the microprocessor 6,
A transition is made to “monitor mode”, and “monitor mode” is prioritized over all user interrupt signals 107. Thus, the debugging work can be continued without executing the defective user interrupt program.

A series of operations in the monitor mode when the "monitor mode" is set by the low-level break signal according to the embodiment of the present invention will be described with reference to FIG. Step-201 When the monitor mode is set by the low-level break signal, command processing for realizing the in-circuit emulator function is executed. Step-202 Next, it is determined whether or not there is a user interrupt from the target system 3. If there is no user interruption, the process returns to step -201 and repeats the command processing. Step-203 If there is a user interrupt, it is determined whether or not the user interrupt is prioritized. In the case of a user interrupt having a lower level than the low-level break signal, the user interrupt is not given priority, so the process returns to step -201 to repeat the processing from the command processing. Step-204 In the case of a user interrupt having a higher level than the low-level break signal, the user interrupt is prioritized, so that the user interrupt processing is executed. Note that a user interrupt can be accepted even during command processing. Step-205 Next, it is determined whether there is a bug in the user interrupt processing. If there is no defect in the user interrupt processing, the process returns to step-201 again, and the processing is repeated from the command processing for realizing the in-circuit emulator function. Step-206 If the user interrupt processing is defective, the target system may run away as described in the problem to be solved by the invention. Step-207 Next, the presence / absence of the privilege break signal 104 is determined. If the privilege break signal 104 is present, the mode transits to the monitor mode, returns to step-201, and the process proceeds to the command processing. have priority. Thereafter, since the defective user interrupt processing (step-204) is not executed, the runaway of the target system 3 can be released from the in-circuit emulator 2 side, and the debugging can be continued. When there is no privilege break signal, target runaway (step-206) remains.

As described above, by adding the interrupt control circuit 5 to the in-circuit emulator 2 and providing a plurality of types of break signals for transitioning to the "monitor mode", the user in the space of the target system 3 can be operated during the "monitor mode". Interrupts can be accepted, and if the target system 3 runs away due to a program defect in the accepted user interrupt, the privileged break signal 104 sets the monitor mode to “monitor mode”. "Monitor mode" can be prioritized, and debugging can be continued.

In the above embodiment, the privilege break signal 104 and the low-level break signal 105 are used as break signals for transitioning to the "monitor mode". A combination of using a low break signal and a high level break signal may be used, or two or more break signals may be provided.

[0041]

As described above, according to the present invention, the interrupt control circuit is added to the in-circuit emulator, and a plurality of types of break signals for transitioning to the monitor mode are provided. Interrupts can be accepted, and if the target system runs away due to a program defect in the accepted user interrupt, the monitor mode is set by a break signal that gives priority to the monitor mode over the user interrupt level. This has the advantageous effect that the monitor mode is prioritized over the user interrupt and debugging can be continued.

[Brief description of the drawings]

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

FIG. 2 is an internal block diagram of an interrupt control circuit of the in-circuit emulator.

FIG. 3 is a block diagram showing input / output of an interrupt controller in a microprocessor of the in-circuit emulator.

FIG. 4 is a diagram showing a series of operations during a monitor mode when the monitor mode is set by a low-level break signal of the in-circuit emulator;

FIG. 5 is a block diagram of a conventional in-circuit emulator.

FIG. 6 is a diagram showing a series of operations during a monitor mode of a conventional in-circuit emulator.

[Description of Signs] 1 Host device 2 In-circuit emulator 3 Target system 4 Emulator control circuit 5 Interrupt control circuit 6 Microprocessor 11 Selector 12 Interrupt controller 13 Microcomputer core 101 Host control bus 102 Break signal 103 Select signal 104 Privileged break signal 105 Low Level break signal 106 Main bus 107 User interrupt signal

Claims (1)

[Claims] An emulator control circuit for generating at least a break signal for transition to a monitor mode and a selection signal thereof; and a plurality of types of break signals for transitioning to the monitor mode when a break signal is received from the emulator control circuit. An interrupt control circuit that selects and outputs one break signal according to a selection signal from the emulator control circuit, and a break signal received from the interrupt control circuit,
When a signal that allows a user interrupt is received, a user interrupt from the target system is received during the monitor mode, and when the break signal received from the interrupt control circuit is a signal that prioritizes the monitor mode over the user interrupt, And a microprocessor which gives priority to the monitor mode over user interrupts.