JPH07175678A - Inspecting device and in-circuit emulator - Google Patents

Abstract

PURPOSE:To provide the in-circuit emulator for detecting the generation of series of desired events with simple configuration. CONSTITUTION:The in-circuit emulator is provided with event detecting parts 3, 4 and 5 for detecting plural events. Then, the emulator is provided with an event timer/counter 9 to be respectively started by detected signals outputted from the respective event detecting parts 3, 4 and 5. This event timer/counter 9 outputs the lapse of time from the generation of respective events to a contorl part 10. Therefore, the control part 10 can recognize which time interval the desired events are generated at and only when series of desired events are continuously generated, a break signal can be transmitted to an emulator part 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting a predetermined electronic circuit. Further, the present invention relates to an in-circuit emulator using the method in this inspection circuit.

[0002]

2. Description of the Related Art In recent years, electronic circuits have become more and more complicated, and various inspection methods have been proposed. Particularly in circuits using a CPU, a so-called in-circuit emulator that emulates the operation of the CPU is widely used. In this in-circuit emulator, it is possible to debug not only the hardware but also the software by emulating the operation of the CPU and halting the operation of the CPU when a predetermined event occurs.

In the conventional in-circuit emulator, it is possible to set an event in the program to be debugged for which a break is desired in the event detection section. As this event, a predetermined instruction code in the program or a predetermined signal is used. Then, when the event detection unit detects the set event, the break signal is generated. Therefore, the break signal thus generated can be used as a trigger to easily inspect the intermediate state of the circuit.

Further, as the circuits and programs become complicated, various methods for detecting the event are required. For example, it is possible to want to generate a break signal only when a plurality of events occur in a certain order. In order to satisfy such requirements, it is possible to set a plurality of events to be detected and the order of their occurrence in the conventional in-circuit emulator. In such an in-circuit emulator that can set multiple events, even if an event other than the desired event occurs during a series of program execution,
The condition for the break signal to occur is not normally affected. For example, when it is attempted to detect that the event B occurs after the event, the break signal is generated even when the event B occurs after the event C occurs after the event A.

In such a conventional in-circuit emulator, there is no means for recognizing that an event other than the event set in the event detector has not occurred, so that the event C is placed between the event A and the event B. It is impossible to recognize whether or not has occurred. For example, in a program having the operation represented by the flowchart shown in FIG. 2, if an attempt is made to generate a break signal only after event A occurs and then event B occurs, event A occurs. Then, the event D is selected in the branch 2, the event C is selected in the branch 1, and then the break signal is generated even when the event B is generated through the process 2 and the branch 2.

As described above, in the conventional in-circuit emulator, it was impossible to distinguish whether a series of events occurred continuously or another event occurred in between. A method for solving such a problem is described in, for example, Japanese Patent Laid-Open No. 3-189834. The in-circuit emulator described here has a means for clearing an event that has been detected once. Have As a result, when it is desired to detect that the events A and B occur successively, when the other events D, C, etc. occur, the above event A is generated.
It is possible to detect that events A and B have occurred consecutively by clearing that the event is detected.

However, this Japanese Patent Laid-Open No. 3-18983
According to the method described in Japanese Patent Laid-Open No. 4, when a large number of program branches exist, a large number of functions for clearing event detection are required.

The present invention has been made in view of the above problems, and an object thereof is to realize an inspection circuit capable of detecting that only a desired series of events has occurred, with a simple structure, and thus to achieve a desired series of events. It is to provide an in-circuit emulator that can send a break signal only when an event occurs.

[0009]

In order to solve the above problems, the present invention according to claim 1 detects a plurality of types of events occurring in a circuit to be inspected, and outputs different detection signals for each of the types. Event detecting means, timer means provided for each of the plurality of types of events, timer means for starting time counting by the event detection signal and outputting a time value signal, the detection signal and the time value signal And a control means for sending a control signal to the circuit to be inspected, and an inspection device.

In order to solve the above-mentioned problem, the present invention according to claim 2 detects a plurality of types of events occurring in the CPU to be emulated, and outputs an event detection signal different for each type. A timer means provided for each of the plurality of types of events, the timer means for starting timekeeping and outputting a time value signal by the event detection signal, and performing a logical operation on the detection signal and the time value signal. An in-circuit emulator comprising: a control means for sending a control signal to the emulated CPU.

In order to solve the above-mentioned problems, the present invention as set forth in claim 3, detects a plurality of types of events occurring in a circuit to be inspected, and outputs a detection signal different for each type, and the event detection means. Counter means that is provided for each of a plurality of types of events, counts the number of times that the event occurs and outputs a count value, and performs a logical operation on the detection signal and the number of times the event occurs, and controls the circuit to be inspected A control device for transmitting a signal, and the inspection device.

In order to solve the above problems, the present invention according to claim 4 detects a plurality of types of events that occur in the CPU to be emulated, and outputs a detection signal different for each type, and an event detection means. A CPU that is provided for each of the plurality of types of events, counts the number of times that the event occurs and outputs a count value, and performs a logical operation on the detection signal and the number of times the event occurs to generate the CPU to be emulated. And an in-circuit emulator for transmitting a control signal to the in-circuit emulator.

In order to solve the above-mentioned problems, the present invention according to claim 5 is the inspection apparatus according to claim 1 or 3, wherein when the event detecting means detects an event, it detects the event. An inspection apparatus including a storage unit for holding a signal, wherein the detection signal is continuously output after an event is detected.

In order to solve the above problems, the present invention according to claim 6 provides the in-circuit emulator according to claim 2 or 4, wherein the event detecting means responds to an event when the event is detected. The in-circuit emulator is characterized in that it includes storage means for holding a detection signal, and the detection signal is continuously output even after an event is detected.

In order to solve the above problems, the present invention according to claim 7 is the inspection apparatus according to claim 1 or 3, characterized in that the control signal is a break signal. .

In order to solve the above-mentioned problems, the present invention according to claim 8 is the in-circuit emulator according to claim 2 or 4, wherein the control signal is a break signal. Is.

In order to solve the above-mentioned problems, the present invention according to claim 9 is the in-circuit emulator according to claim 2, characterized in that the timer means counts the system clock. Is an in-circuit emulator.

In order to solve the above-mentioned problems, the present invention according to claim 10 is the in-circuit emulator according to claim 2, characterized in that the timer means counts bus cycles to perform timekeeping. Is an in-circuit emulator.

In order to solve the above-mentioned problems, the present invention according to claim 11 is the in-circuit emulator according to claim 2, characterized in that the timer means counts an instruction cycle to perform timekeeping. Is an in-circuit emulator.

In order to solve the above problems, the present invention according to claim 12 provides the inspection apparatus according to claim 3,
The counter means is a counter that counts up or down depending on the occurrence of an event, and is a counter means that can be switched between up-counting and down-counting by an instruction signal from the outside.

In order to solve the above problems, the present invention according to claim 13 provides the in-circuit emulator according to claim 4, wherein the counter means is a counter that counts up or down depending on the occurrence of an event. The in-circuit emulator is a counter means for switching between up-counting and down-counting according to an instruction signal from the outside.

[0022]

The control means according to the present invention sends the control signal based not only on the event detection signal but also on the time value signal indicating the time from the occurrence of the event. The detection signal is sent out only when a series of events of.

The control means in the present invention according to claim 3 or 4 sends the control signal based not only on the event detection signal but also on the count value indicating the number of times the event has occurred. The detection signal is sent out only when is generated. Since the event detecting means according to the present invention according to claim 5 or 6 includes the storage means, the event detecting means continuously outputs the detection signal even after the occurrence of the event ends. Therefore, the control unit does not need to store the occurrence of the event.

Since the control signal according to the present invention of claim 7 is a break signal, it stops the operation of the circuit to be inspected and shifts it to the halt state. Therefore, various signals can be easily inspected.

Since the control signal in the present invention according to claim 8 is a break signal, the operation of the CPU to be emulated is stopped, and the CPU enters the halt state. Therefore, various signals can be easily inspected.

The timer means in the present invention according to claim 9 measures the time by counting the system clock. Therefore, it is possible to measure time according to the circuit operation.

The timer means in the tenth aspect of the present invention counts the time by counting the bus cycles. Therefore, it becomes possible to measure time according to the operation of the CPU.

The timer means in the present invention according to claim 11 clocks time by counting instruction cycles. Therefore, it becomes possible to measure the time according to the execution of the instructions of the program.

The counter means in the present invention according to claim 12 or 13 can switch between up-counting and down-counting by an instruction signal from the outside. Therefore, by combining down-counting and up-counting according to the occurrence of various events, it is possible to send the control signal only when a desired series of events occurs.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 shows a block diagram of a configuration of an in-circuit emulator which is a preferred embodiment of the present invention. As shown in FIG. 1, an emulator unit 1 that emulates the operation of a CPU that is an emulation target of this in-circuit emulator is connected via an emulation bus 2 to a circuit to which this CPU is to be attached. There is.

As shown in FIG. 1, a plurality of event detectors 3, 4, 5 are also connected to the emulation bus 2, and various signals included in the emulation bus 2 have predetermined values. Is detected, that is, the event has occurred. Each event detector 3,
Corresponding storage units 6, 7, and 8 are provided in the units 4 and 5, respectively. Then, when an event occurs, the detection signals output from the event detection units 3, 4, and 5 are respectively held and supplied to the control unit 10.

Then, the detection signals from the respective event detectors 3, 4, 5 are also supplied to the event timer / counter 9. The event timer / counter 9 starts time counting by the detection signal and notifies the control unit 10 of the elapsed time from the generation of the detection signal.

A feature of this embodiment is that an event timer / counter 9 is provided for measuring the elapsed time after the detection signal is generated. Then, since the control unit 10 is notified of the elapsed time from the detection of the event, the control unit 10 can know the occurrence time interval of each event that occurs.

The operation of the in-circuit emulator according to the first embodiment will be described below with reference to the flow chart shown in FIG.

As described above, the emulator section 1 emulates the operation of the CPU to be emulated. Then, the event detectors 3, 4, 5 constantly monitor the emulation bus 2. Then, it is always inspected whether or not it matches the preset event condition, and if they match, the corresponding storage unit 6,
The detection signal is sent to 7 and 8. And this storage unit 6,
7 and 8 constantly output the stored contents held therein to the control unit 10.

A target event to be detected is set in each of the event detectors 3, 4, and 5. Then, in the event timer / counter 9, the number of system clocks from the occurrence of the target event set in the event detectors 3, 4, and 5 to the occurrence of the next target event, the bus cycle, or the instruction cycle. The number is set. These values set in the event timer / counter 9 are determined by the debug target program. The event timer / counter 9 counts the system clock, the bus cycle, or the instruction cycle, and measures the time by this count.
This event timer / counter 9 is a detection signal output from the above-mentioned event detection unit 3, 4, 5 or the control unit 1.
A control signal output from 0 starts the counting of the system clock and the like, and the control unit 10 has information indicating whether the count value which is a time value has reached a predetermined set value.
Be transmitted to.

The control unit 10 includes the storage units 6, 7, 8 described above.
Also, each signal output from the event timer / counter 9 is input, the signals are logically operated, and a break signal is generated. The generated break signal is sent to the emulator section 1 to control the emulator section 1.

Therefore, for example, in the flow chart shown in FIG. 2, when it is desired to generate the break signal immediately after the event A occurs, that is, only when the event B occurs through the process 2 and the branch 2. Is a value slightly larger than the time between events when event A occurs immediately after event A /
The counter 9 is set. As a result, for example, when the event B occurs after the processing of the event A, the event D, and the event C continues, the event A and the event B are generated.
It is possible to suppress the generation of the break signal when and are separated in time.

Second Embodiment In the first embodiment, the event timer / counter 9 is used.
Was counting pulse signals such as the system clock. However, it is also preferable that the event timer / counter 9 is configured to count the number of event occurrences. The event timer / counter 9 in the second embodiment increments or decrements the count value when the event detection units 3, 4, and 5 output the detection signal. That is, the event timer / counter 9 operates as an up counter or a down counter. Whether to operate as the up counter or the down counter is controlled by an up / down instruction signal from the outside. In addition,
This up / down instruction signal is omitted in FIG.

The characteristic feature of the second embodiment is that the event timer / counter 9 inputs the detection signals output from the event detection units 3, 4, and 5 to count the number of occurrences of the set event. Is what you are doing. Other configurations in the second embodiment are similar to those in the first embodiment.

A count value is preset in the event timer / counter 9, and the event detectors 3, 4, 5
The up / down count is performed according to the detection signal output by. The count value is always sent to the control unit 10.

The control unit 10 inputs signals from the storage units 6, 7 and 8 and the event timer / counter 9 as in the first embodiment and performs a predetermined logical operation to generate a break signal.

Therefore, in the second embodiment, only when the event B occurs immediately after the event A occurs and the break signal is to be output, the following setting / control may be performed.

First, the events A and B are set in the event detectors 3 and 4, respectively. Then, the process 3 in the flowchart shown in FIG. 2 is set in the event detection unit 5. Then, the event timer / counter 9 is instructed to down count the detection signals from the event detection units 3 and 4, and is instructed to up count the detection signals from the event detection unit 5. deep. Furthermore, the counter initial value of the event timer / counter 9 is set to "2". When the debug target program is executed after such preparation, the event counter value changes from "2" to "1" when the event A occurs after the branch 1 in the flowchart shown in FIG. 2 is executed. This is because the event timer / counter 9 is set to the down count for the event detection unit 3 that detects the event A as described above.

Next, when the event B occurs, the event counter value changes from "1" to "0", and this "0" is transmitted to the control unit 10. Then, the control unit 10 checks the signals output from the storage unit 6 and the storage unit 7 to know that the event A and the event B are generated based on the “0”. As a result, a break signal is generated for the emulator section 1.

On the other hand, if the event B does not occur, the event counter value does not change, and the process 3 in the flowchart shown in FIG. 2 is executed. As a result, the event counter value returns from "1" to "2". Hereinafter, the processing shifts to the branch 1 in this state. As described above, the event detector 5
Processing 3 is set, the event detection unit 5 sends a detection signal of this processing 3 when the processing 3 is executed. Then, as described above, the event timer / counter 9 is instructed to count up with respect to the detection signal from the event detection unit 5, so that the event counter value is from "1" to "2" as described above. That is, it will return to the initial value.

As described above, in the second embodiment, when the events A, D, C, and B occur in this order, the break signal does not occur, and the event B immediately follows the event A. It becomes possible to generate a break signal only when occurs.

[0049]

As described above, according to the first aspect of the present invention, since the timer means for counting the time by the occurrence of the event is provided, the inspection device capable of performing the inspection in consideration of the event occurrence time interval is provided. It has the effect of being obtained.

According to the invention of claim 2, similarly to the invention of claim 1, there is an effect that an in-circuit emulator capable of performing an inspection in consideration of a time interval between events can be obtained.

According to the third aspect of the present invention, since the counter means for counting the number of times an event has occurred is provided, when an extra event occurs between the event to be detected and the event. Has an effect of obtaining an inspection apparatus that can recognize that the desired condition is not satisfied.

According to the invention described in claim 4, as in the invention described in claim 3, the control signal can be sent to the CPU to be emulated only when the events to be detected continuously occur. It has an effect that an in-circuit emulator can be obtained. According to the invention of claim 5, in the inspection apparatus of claim 1 or 3,
Since the storage means for holding the detection signal is included, there is an effect that the inspection device in which the logical operation in the control means is easy can be obtained.

According to the invention of claim 6, the in-circuit emulator according to claim 2 or 4 includes a storage means for holding a detection signal. Similarly to the above, there is an effect that an in-circuit emulator in which the logical operation in the control means is easy can be obtained.

According to the invention of claim 7, claim 1
Alternatively, in the inspection apparatus according to the third aspect, since the control signal is the break signal, it is possible to obtain an inspection apparatus capable of breaking the circuit to be inspected when a predetermined event is detected.

According to the invention of claim 8, claim 2
Alternatively, in the in-circuit emulator according to the fourth aspect, an in-circuit emulator capable of sending a break signal to the CPU when a predetermined event is detected can be obtained as in the inspection device according to the above claims. Have.

According to the invention described in claim 9, in the in-circuit emulator according to claim 2, the timer means counts the system clock by counting the system clock. Therefore, it is possible to obtain an in-circuit emulator capable of easily performing accurate timekeeping.

According to the tenth aspect of the invention, in the in-circuit emulator according to the second aspect, the timer means counts the bus cycle, so that the CPU
This has the effect of providing an in-circuit emulator capable of counting in units of operations.

According to the invention described in claim 11, in the in-circuit emulator according to claim 2,
The timer means counts instruction cycles. Therefore, it is possible to obtain an in-circuit emulator capable of counting corresponding to the execution of the instruction of the CPU.

According to the twelfth aspect of the invention, in the inspection apparatus according to the third aspect, the counter means switches between up-counting and down-counting according to an instruction signal from the outside. Therefore, by selecting whether to down-count or up-count depending on the event, there is an effect that it is possible to obtain an inspection device that can easily detect the occurrence of a complicated event.

According to the invention described in claim 13, in the in-circuit emulator according to claim 4,
Similar to the above-mentioned claim 12, since it is possible to instruct switching between up-counting and down-counting, it is possible to obtain an in-circuit emulator capable of detecting the occurrence of a complicated event.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an in-circuit emulator that is a preferred embodiment of the present invention.

FIG. 2 is an example of a flowchart of a program in which it is difficult to detect events that occur continuously.

[Explanation of symbols]

 1 Emulator Section 2 Emulation Bus 3, 4, 5 Event Detection Section 6, 7, 8 Storage Section 9 Event Timer / Counter 10 Control Section

Claims (13)

[Claims] 1. An event detection means for detecting a plurality of types of events occurring in a circuit to be inspected and outputting a detection signal different for each type, and a timer means provided for each of the plurality of types of events, By the event detection signal, a timer means for starting timing and outputting a time value signal, a control means for logically operating the detection signal and the time value signal, and sending a control signal to the circuit to be inspected, An inspection apparatus comprising: 2. Event detecting means for detecting a plurality of types of events occurring in a CPU to be emulated and outputting a detection signal different for each type, and timer means provided for each of the plurality of types of events. A timer means for starting timekeeping by the event detection signal and outputting a time value signal; and a control means for logically operating the detection signal and the time value signal and sending a control signal to the emulation target CPU. And an in-circuit emulator including. 3. An event detecting means for detecting a plurality of types of events occurring in a circuit to be inspected and outputting a detection signal different for each type, and a number of times the events occur, which are provided for each of the plurality of types of events. Counter means for counting and outputting a count value, and control means for performing a logical operation on the detection signal and the number of occurrences of the event and sending a control signal to the circuit to be inspected. Inspection device. 4. Event detecting means for detecting a plurality of types of events occurring in an emulated CPU and outputting a detection signal different for each type, and the event detecting means provided for each of the plurality of types of events. Counter means for counting the number of times and outputting a count value; and control means for logically operating the detection signal and the number of times the event has occurred and sending a control signal to the CPU to be emulated. And an in-circuit emulator. 5. The inspection apparatus according to claim 1, wherein the event detection unit includes a storage unit that holds a detection signal corresponding to the event when the event is detected, and the detection signal is the event detection. An inspection device characterized by being continuously output afterward. 6. The in-circuit emulator according to claim 2, wherein the event detection unit includes a storage unit that holds a detection signal corresponding to the event when the event is detected, and the detection signal is the event. An in-circuit emulator that is continuously output even after detection. 7. The inspection apparatus according to claim 1, wherein the control signal is a break signal. 8. The in-circuit emulator according to claim 2 or 4, wherein the control signal is a break signal. 9. The in-circuit emulator according to claim 2, wherein the timer means counts a system clock to perform timekeeping. 10. The in-circuit emulator according to claim 2, wherein the timer means counts bus cycles to count time. 11. The in-circuit emulator according to claim 2, wherein the timer means counts instruction cycles to count time. 12. The inspection apparatus according to claim 3, wherein the counter means is a counter that counts up or down when an event occurs, and the counter is switched between up-counting and down-counting by an instruction signal from the outside. An inspection apparatus, which is a counter means. 13. The in-circuit emulator according to claim 4, wherein the counter means is a counter that counts up or down when an event occurs, and switches between up-counting and down-counting according to an instruction signal from the outside. An in-circuit emulator, which is a counter means that can be used.