JPH05189393A - Reset processing circuit - Google Patents

Abstract

PURPOSE:To smoothly perform a proper reset processing corresponding to the cause of a reset which takes place without complicating the hardware configulation of a CPU board and the processing of CPU software. CONSTITUTION:A reset processing circuit 13 stores information indicating the type (corresponding to Nos. 101 to 104) of a reset signal to be generated within a RAM 131. Based on the information indicating the type of the reset signal stored in the RAM 131, the corresponding reset processing is read out of the table data of the RAM 131 and the read-out reset processing is executed via a reset processing circuit 13. Thus, a part or all of peripheral circuits 12-1 to 12-3 are initialized or a re-setting processing, etc., of a software parameter in a CPU 11 can be executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reset processing circuit for resetting a CPU or its peripheral circuits.

[0002]

2. Description of the Related Art Conventionally, in a data processing device composed of a CPU and its peripheral circuits, there are various reset causes (types). For example, power-on reset performed at power-on, runaway of software for operating the CPU. There is a watchdog timer reset for detecting and resetting, and an inter-CPU reset in which a plurality of CPUs reset each other's CPUs. Therefore, when a reset is applied, the range of the peripheral circuit of the CPU to be reset varies depending on the various causes for applying the reset.

By the way, in the case of a multi-processing system in which a plurality of CPU boards equipped with a CPU and its peripheral circuits are connected by a common bus, a reset occurs in its own board. When it becomes necessary to make a reset request to the board of the above, why is the reset board reset, or is the reset board the own board? Whether or not it is a board must be discriminated, and depending on the discrimination result, the initialization on the hardware of the peripheral circuit must be carried out or the parameter on the software must be initialized. For this reason,
If there is no circuit that holds the cause information of the generated reset and identifies this, not only the hardware configuration related to the reset or the processing on the software may be complicated, but also the function is seriously hindered. It had the drawback of causing

[0004]

As described above, a plurality of Cs are used.
In a multi-processing system configured by connecting PU boards with a common bus, there are various reset causes, and the processing contents on the hardware or software may differ depending on the reset causes. Therefore, when a reset occurs, it is necessary to save the cause of the reset, identify the contents, and then execute the reset process in the corresponding range. However, in the conventional system, since there is no circuit for holding the reset cause information or a circuit for identifying the reset cause content, not only the hardware configuration related to the reset or the process on the software becomes complicated, There was a drawback in that it also caused a great hindrance in terms of functionality.

Therefore, the present invention eliminates the above-mentioned drawbacks, and
To provide a reset processing circuit capable of smoothly performing an accurate reset processing corresponding to a cause of a reset that has occurred without complicating the hardware configuration of the U-board and the software processing of the CPU. It is an object.

[0006]

A reset processing circuit according to the present invention stores a storage means for storing data indicating the contents of reset processing corresponding to the type of reset and information for identifying the type of reset that has occurred. A storage unit for storing the data, a search unit for searching the data in the storage unit based on the information stored by the storage unit and reading out a corresponding reset process; and a reset process read by the search unit. It has the structure provided with the initialization means to perform.

[0007]

In the reset processing circuit of the present invention, the storage means stores data indicating the content of the reset processing corresponding to the type of reset. The storage unit stores information that identifies the type of reset that has occurred. The search means searches the data in the storage means based on the information stored by the storage means and reads the corresponding reset processing.
The initialization unit executes the reset process read by the search unit.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a multi-processing system equipped with a reset processing circuit of the present invention. Reference numerals 1-1 to 1-3 denote CPU boards equipped with a CPU, peripheral circuits thereof, and a reset processing circuit of the present invention, and the CPU boards are connected by common buses 2 and 3.

FIG. 2 is a diagram showing a detailed configuration example of the CPU board 1-2 described above. Reference numeral 11 denotes a CPU that performs various types of information processing and also performs reset processing,
Is a peripheral circuit of the CPU 11, 13 is a peripheral circuit 12-1
12-13 is a reset processing circuit that resets the reset cause (type) and stores the reset processing data corresponding to the contents of the reset cause.
Have one. Reference numeral 14 is a backup power supply unit that backs up the power of the reset processing circuit 13. here,
Various reset signals are input to the reset processing circuit 13, 101 is a reset signal input from the CPU board 1-1, and 102 is a reset signal input from the CPU board 1-3. Reference numeral 103 denotes a power-on reset signal, and 104 denotes a watchdog timer reset signal. The configurations of the CPU boards 1-1 and 1-3 are the same as in this example.

Next, the operation of this embodiment will be described. For example, when the CPU board 1-1 issues a reset request to the CPU board 1-2 via the common bus 2, the CPU board 1-
The reset signal 101 is input to the second reset processing circuit 13. The reset processing circuit 13 uses the reset signal 1
When 01 is input, a flag is set in a predetermined area of the RAM 131 as shown in FIG. 3 to store the information indicating that the input reset signal is input from the CPU board 1-1. Therefore, since the reset signal 101 is input in the area shown in FIG.
The flag "1" is set in the portion corresponding to "" and the other portions are "0". The CPU 11 goes to check the contents of the RAM 131 of the reset processing circuit 13 by a periodic timer interruption, and when it knows that the reset signal is input because the flag is set, it shifts to the reset processing. In this reset process, the CPU 11 refers to the table data in the RAM 131 indicating the contents of the reset process to be performed corresponding to the type of the input reset signal.

FIG. 4 is a diagram showing an example of the table data stored in the RAM 131. This indicates which peripheral circuit should be reset, that is, initialized, or whether initialization such as parameter reset on software should be performed according to the type of the input reset signal. When the reset signal 101 is input as in the above example, the CPU 11 detects the peripheral data 1 from the table data.
Knowing that the 2-1 should be initialized, the peripheral circuit 12-1 is initialized through the reset processing circuit 13, and finally, the area shown in FIG. To finish. When the input reset signal is the watchdog timer reset signal 104, the CPU 11 reads the table data and the peripheral circuit 12 from the table data.
Knowing that the parameters on software must be reset as well as initializing -1 to 12-3,
The initialization process corresponding to this is performed, and finally, the area shown in FIG. 3 in the RAM 131 is cleared in the same manner as above, and the initialization process is completed.

According to this embodiment, when the reset signal is generated, the reset processing circuit 13 outputs the information indicating the kind of the reset signal (corresponding to the cause of the reset generation) to the RA.
In order to save the data in the M131, the CPU 11 must reset the range from the data table stored in the RAM 131 to the peripheral circuit based on the stored information, or the software reset. It is possible to read out the information as to whether or not it should be performed and perform the reset processing according to this information. For this reason, even in a multi-processing system, each CPU board
Each CPU board can smoothly perform an appropriate reset process according to the type of reset that has occurred, without complicating the hardware configuration of the hardware and the processing on the software. In the above embodiment, the reset processing of the CPU board 1-2 has been described, but other CPU boards 1-1.
Alternatively, the reset process of 1-3 is also the same and has the same effect.

[0013]

As described above, according to the reset circuit of the present invention, it is possible to cope with the cause of the reset that has occurred without complicating the hardware configuration of the CPU board and the software processing of the CPU. An accurate reset process can be smoothly performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a multi-processing system equipped with a reset processing circuit of the present invention.

2 is a block diagram showing a detailed example of a CPU board shown in FIG.

FIG. 3 is a diagram showing an example of an area for storing information indicating the type of reset signal set on the RAM shown in FIG.

4 is a diagram showing an example of table data stored in a RAM shown in FIG.

[Explanation of symbols]

1-1 to 1-3 ... CPU board 2, 3 ... Common bus 11 ... CPU 12-1 to 12-
3 ... Peripheral circuit 13 ... Reset processing circuit 14 ... Backup power supply unit 131 ... RAM

Claims (1)

[Claims] 1. Storage means for storing data indicating the contents of reset processing corresponding to the type of reset, and storage means for storing information for identifying the type of reset that has occurred.
Retrieval means for retrieving the data in the storage means on the basis of the information stored by the storage means to retrieve the corresponding reset processing, and initialization means for executing the reset processing read by the retrieval means. And a reset processing circuit.