JPH0448361A - Bus monitoring device - Google Patents

Abstract

PURPOSE:To prevent over-capacity occurring and to preserve the history of a bus signal successively extending over a long period by providing a restoration circuit for compressed information read out from buffer memory,a a memory device to store the history compressed at the buffer memory. CONSTITUTION:The bus signal received by a receiver 11 is compressed at a compression circuit 12, and is recorded on the buffer memory 13 sequentially, and the history of the bus signal is generated in the buffer memory 13, and also, the compressed information read out from the buffer memory 13 is restored to a state before compression at the restoration circuit 14, and is sent out to an internal bus 15. Also, the memory device 17 is connected to the buffer memory 13 via an external input/output control circuit 16. Since the compression is performed at the compression circuit 12 in advance, history information more than ever can be preserved in the buffer memory 13, which prevents the over-capacity occurring, and also, since the external memory device 17 is used, the history of the bus signal can be preserved extending over the long period successively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bus monitor device that creates a history of bus signals in a buffer memory for analyzing bald spots and failures in a data processing system having a bus structure.

[Prior Art J] The one shown in FIG. 2 has been known as a bus monitor device that creates a history of bus signals in a buffer memory in order to analyze bugs and failures in a data processing system having a bus structure.

This bus monitor device is disclosed in Japanese Patent Application Laid-Open No. 61-41055, and when the start of nomadic monitoring is instructed, the bus signal, which is information on the system bus 2, is sequentially passed through the sense amplifier 1 to the buffer memory 3. By writing in , it becomes the history of the Nox signal. The information written in the knob/fa memory 3 is then read out by the microprocessor 6.

The information written in the buffer memory 3 is read by the microprocessor 6 setting an address in the address counter 4 and giving a read instruction to the control circuit 9.

Then, the information read from the buffer memory 3 is edited by the microprocessor 6 and outputted to the external input/output device on the illustrated path, thereby checking the operation history.

In FIG. 2, reference numeral 5 indicates a mode switch that sets the operating mode of the bus monitor device, and reference numeral 7 indicates a communication control circuit that executes data exchange between the microprocessor 6 and the external input/output device as shown. Reference numeral 8 denotes a bus drive circuit used for exchanging data between the CPU (as shown) and the microprocessor 6 connected to the system bus 2.

[Problems to be Solved by the Invention] However, in the bus monitor device having the above-described configuration, the amount of data to be written exceeds the capacity of the buffer memory 3 during the writing process of history information, and the history information to be recorded is lost. There was a high possibility that an inconvenience would occur where part of the data could not be recorded.

Furthermore, the amount of history information that can be saved is limited to a relatively small amount, making it impossible to continuously save the history of bus signals over a long period of time.

The present invention has been made in view of the above-mentioned circumstances, and is capable of storing a large amount of history information. Therefore, during the writing process of history information, some of the history information that should be recorded may not be recorded due to overcapacity. It is an object of the present invention to provide a bus monitor device which is less likely to cause the inconvenience of data being lost and which can also be used to continuously store the history of bus signals over a long period of time.

[Means for Solving the Problems] A bus monitor device according to the present invention is a device that creates a history of bus signals in a buffer memory for analyzing bugs and failures in a data processing system having a bus structure.

Specifically, it includes a compression circuit that compresses a bus signal of the data processing system and records it in the buffer memory, a restoration circuit that restores the compressed information read from the buffer memory, and a compression circuit that compresses and records the bus signal of the data processing system in the buffer memory. The configuration includes a storage device that stores the history created in the state in which the data is created.

[Function] The bus monitor device according to the present invention creates a history of bus signals in the buffer memory, but since the data recorded in the buffer memory is compressed in advance by a compression circuit, the bus monitor device according to the present invention can improve the bus signal history without increasing the capacity of the buffer memory. It becomes possible to store a large amount of historical information in the buffer memory.

Therefore, the inconvenience that part of the history information that should be recorded cannot be recorded due to capacity overflow during the history information writing process is less likely to occur.

Moreover, the bus monitor device according to the present invention is equipped with a storage device that stores the history created in a compressed state in the buffer memory, and the amount of history information that can be stored by the storage device can be further expanded. This makes it possible to continuously store the history of bus signals over a long period of time.

[Embodiment] FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

The bus monitor device of this embodiment monitors bus signals sent on a system bus in a data processing system having a bus structure, and creates a history of the bus signals in a buffer memory for bug and failure analysis. It is.

In the figure, reference numeral 10 is a system bus to be monitored.

A bus signal sent to the system bus 10 is received by a receiver 11, which is a sense amplifier.

The bus signal received by the receiver 11 is compressed by the compression circuit 12 and sequentially recorded in the buffer memory 13, thereby creating a history of the bus signal in the buffer memory 13.

Furthermore, the compressed information read from the buffer memory 13 can be restored to the state before compression by the restoration circuits 1 and 4 and sent to the internal bus 15.

Further, a storage device 17 is connected to the buffer memory 13 via an external input/output control circuit 16.

In this embodiment, the storage device 17 is a magnetic disk device, and has a much larger capacity than the buffer memory 13, and can store a large number of histories created in a compressed state in the buffer memory 13.

Further, on the internal bus 15, a microprocessor 1
9, a control circuit 20, a work memory 21, etc. are connected thereto.

The microprocessor 19 controls the operation of each part of the bus monitor device of this embodiment.

The control circuit 2o controls the operations of the compression circuit 12, buffer memory 13, and decompression circuit 14 according to instructions from the microprocessor 19.

Specifically, when performing read/write processing on the buffer memory 13, an address on the buffer memory 13 is specified.

The work memory 21 is a storage circuit having a storage capacity several times that of the buffer memory 13, and is used to temporarily hold the history information restored by the restoration circuit 14.

The data held in the work memory 21 is used by the microprocessor 19 to analyze history information.

The data compression method in the compression circuit 12 is Modified READ, which is used in facsimiles and the like.
method is adopted. The data compressed by the compression circuit 12 is written to the buffer memory 13 in units of bytes.

In the restoration circuit 14, in accordance with the compression circuit 12,
Data is restored using the divided READ method.

When the information to be recorded in the buffer memory 13 is only an address on the system bus 10, the address output from the processor executing the program onto the system bus has locality. Therefore, there is a high probability that the address information to be stored will be almost the same except for the lower number bat. Focusing on this, Modified REA
When data is compressed using the D method, higher compression efficiency can be obtained, and the amount of information that can be stored in the buffer memory 13 can be further increased.

In such a bus monitor device, the data recorded in the buffer memory 13 is compressed in advance by the compression circuit 12, so that a larger amount of history information can be stored in the buffer memory 13 without increasing the capacity of the buffer memory 13. becomes possible.

Therefore, the inconvenience that part of the history information that should be recorded cannot be recorded due to capacity overflow during the history information writing process is less likely to occur.

Moreover, by moving the history information created in the buffer memory 13 to the storage device 17 at the appropriate time, the buffer memory
At the same time, since the amount of history information that can be stored by the storage device 17 is further expanded, it is also possible to continuously store the history of bus signals over a long period of time. become.

[Effects of the Invention] As is clear from the above description, the bus monitor device according to the present invention creates a history of bus signals in the buffer memory;
Since the data recorded in the buffer memory is compressed in advance by a compression circuit, it is possible to store a larger amount of history information in the buffer memory without increasing the capacity of the buffer memory.

Therefore, the inconvenience that part of the history information that should be recorded cannot be recorded due to capacity overflow during the history information writing process is less likely to occur.

Moreover, the bus monitor device according to the present invention is equipped with a storage device that stores the history created in a compressed state in the buffer memory, and the amount of history information that can be stored by the storage device can be further expanded. This makes it possible to continuously store the history of bus signals over a long period of time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of a conventional bus monitor device. 10...System bus, 11...S/- bus
12... Compression circuit, 13... Buffer memory, 14. ... Restoration circuit, 15 ... Internal bus, 16 ... External input/output control circuit, 17 ...
・Storage device, 19...Microprocessor, 2
0...Control circuit, 21...Work memory. FIG. 1 is a block diagram of an embodiment of the present invention.

Claims (1)

[Scope of Claims] A bus monitor device that creates a history of bus signals in a buffer memory for analyzing bugs and failures in a data processing system having a bus structure, the bus monitoring device compressing bus signals of the data processing system and compressing the bus signals in the buffer memory. A compression circuit for recording in a memory, a restoration circuit for restoring based on the compressed information read from the buffer memory, and a storage device for storing the history created in a compressed state in the buffer memory. A bus monitor device featuring: