JPH02230446A - Fault processing method for channel controller - Google Patents

Abstract

PURPOSE:To surely recover a fault by analyzing the factor and the range of a fault and using an optimum channel number to report the fault to a central processing circuit when the fault is detected in a channel controller while no specific channel device is controlled. CONSTITUTION:The occurrence of a fault is reported to a CPU 1 when the fault is detected in a channel controller 4 which controls the plural channel devices 5 - 7 in time division in a state where the controller is not connected to any channel device. In other words, the state of the component hardware is taken out together with the state of the control information, and an executing locus of a microprogram. Then the factor and the range of the fault are analyzed and an optimum channel number to be used is selected to report the fault to a CPU 1. Thus the faulty one of the devices 5 - 7 are specified and this fault is surely recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for handling failures detected in a channel control device that controls a plurality of channel devices in a time-sharing manner.

[Conventional technology]

In recent years, the channel devices that control data transfer between the central processing unit and the human output device have become smaller and the central processing unit has become more efficient. It has been characterized as an output processing device. On the other hand, the external device called the channel control device cannot be recognized from the central processing unit side.
Failures due to abnormality detection in the channel control device must be reported as channel device failures. However, depending on the type of failure of the channel control device, it may not be possible to immediately identify a faulty channel among any channels it controls. For example, if a failure occurs in the channel control unit while searching for a control request interrupt from the channel control unit, a control request interrupt from the channel, or a channel activation instruction from the central processing unit, the channel number that caused the failure is immediately retrieved. may not be able to be identified. Therefore, in the past, the following methods were used: (1) Reporting to the central processing unit using an "external device abnormality interrupt," (2) Using a predetermined channel number, for example, the lowest number among the channel devices controlled by oneself. Either the channel control device reports to the central processing unit using the number of the last channel it controlled, or it temporarily suspends the report to the central processing unit when a failure is detected and performs channel control. When the device generates a control request interrupt from a channel or a channel activation request from the central processing unit, whether the device reports it to the central processing unit using a "human output interrupt" using the channel number that made these requests. It was by that method.

[Problem to be solved by the invention]

However, method (2) has the disadvantage that all channels controlled by the channel control device must undergo failure recovery processing. In other words, "interrupt due to external device error"
Subsequent failure recovery processing must be performed on multiple channel devices, which may impair system processing speed and availability. On the other hand, in the case of the method (2), since the channel determined to be abnormal is not based on actual operation, there is a risk that the block diagram 1 will not be recovered. Furthermore, although recovery processing is performed with a fairly high probability in method (2), there is no guarantee that recovery processing will be performed reliably in all cases. Furthermore, methods ① and ③ have the disadvantage that if the same failure occurs again after failure recovery processing, an "interrupt" will occur and the processing speed of the system will decrease due to a series of unnecessary failure processes. be.

(Means for Solving the Problems) A fault handling method for a channel control device according to the invention is a method for processing a fault detected in a channel control device that controls a plurality of channel devices in a time-sharing manner. When a failure is detected in the channel control device while not controlling any specific channel device and searching for a control request from the channel device or a startup instruction for the channel device from the central processing unit. , temporarily suspends reporting of the failure to the central processing unit, and releases the suspension upon receiving a control request from a channel device or a startup instruction for a channel device from the central processing unit, and reports the failure to the channel control device. After forcibly terminating the operation request, the state of the hardware included in the channel control device that constitutes the channel control device, the state of the control information used to control the channel device, and the configuration of the channel device Analyze the cause and scope of the failure by extracting the execution trajectory of the microflow controller that controls the hardware that occurs. From 7.7, the optimal channel number to be used when reporting the failure to the central processing unit is determined. Select
This channel number is used to report a failure to the central processing unit.

[For production]

Therefore, if the channel control device is not controlling any specific channel device and the channel control device is searching for a control request from the channel device or a startup instruction for the channel device from the central processing unit, When a fault is detected in the system, the channel device in which the fault has occurred can be identified, and fault recovery processing can be performed reliably.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a connection configuration diagram of human output channels.

The human output processing device 2 includes a plurality of channels 5 to 7 and a channel control section 4 that controls the channels 5 to 7 in a time-sharing manner, and is connected to the central processing device 1 via a human output interface 9. . Each channel 5 to 7 is connected to the human output device 3 via an I/O interface 11, and further connected to the channel control unit 4 via a channel interface 10. The channel control section 4 has a control storage (CS) S, and controls channels 5 to 7 according to a microprogram stored therein.

Next, the operation of this embodiment will be explained using the CS read failure processing of the channel control unit 4 as an example.

FIGS. 2 and 3 are block diagrams of the processing flow of the microprogram. The processing flow of the microprogram can be classified into three routines.

The first routine is ``Idonore'' Noretin, and J
The current node is waiting for a control request from channels 5 to 7 or a channel activation instruction from central processing unit 1.

Typically, this routine executes microinstructions for self-diagnosis. The second routine is the "JV channel control" routine, and when a control request from channels 5 to 7 occurs, the microprogram is forcibly branched to the start address of the routine (called BI: break-in). ,
Start processing. The third routine is a "failure handling" routine initiated by a CS8 read error. A forced branch operation to a "fault handling" routine is called an STL (steal) operation to distinguish it from a BI operation.

FIG. 2 is a flowchart of processing when the microprogram detects a CS8 read error while executing the "channel control" routine. A "channel control" request occurs at points A and C, and the microprogram transitions from the "idle" routine to the "channel control" routine. At point B, the "channel control" routine processing is completed.
Back to the "idle" routine again. The behavior at this time is B
The I operation is called a BO (break out) operation.

In the example of FIG. 2, no read failure of CS8 occurs between A and B, and a "channel control" request occurs again at point C, causing a BI operation. If a reading failure occurs in the CS8 at point D during the request, the microprogram starts "failure handling" by STL operation. After performing failure recovery processing such as rewriting the CS8, it reports to the central processing unit 1 that a failure has occurred in the channel that was performing "channel control", and completes the "failure processing". In this way, a fault in the channel control section 4 detected during "channel control" can be reported as a fault in the channel that was under control of the channel control section 4. On the other hand, when the channel controller 4 is not controlling any channel, that is, when the channel controller 4 is not controlling any channel, it cannot be determined that a channel controller failure detected during "idle" is a failure in the other channel.

FIG. 3 is a flowchart of failure handling according to this embodiment. When a reading failure of CS8 is detected at point A of the "idle" routine, an attempt is made to start the "failure processing" routine by STL operation, but since the fault is in the channel control section detected during the "idle" routine, the processing is terminated. The start of is suppressed. This inhibited state continues until point B where a "channel control" request occurs, at which point control of the "failure handling" q routine is started in conjunction with the BI operation. Therefore, in the "failure handling" routine after the Bl operation, the channel control unit failure can be treated as a failure of a specific channel. At this time, the operation of the "failure processing" routine will be explained using FIG. FIG. 4 is an embodiment of the tree invention, and shows an example of the structure of a portion of the channel control unit 4 that is related to the invention. CS8
The microinstruction read from the CS read register 12
is set, and its operation section becomes an input to the decoding circuit 16 via the signal line 20. The decoded output of this decode circuit 16 is given to each part of the device, thereby executing the corresponding microinstruction. On the other hand, normally the address part of the CS read register 12 is
This is set in the S address register 21 and given to CS8 as the address of the next microinstruction. A control request from the channel arrives through the signal line 24, and when it is accepted by the request selection circuit 14, the control request is sent to the control request reception signal line 25.
is excited. The channel control indication latch circuit 15 is set by this excitation of the control request reception signal line 25, and the BI address {l'4 line 30 is set in the CS address register 21 through the signal line 23. In other words, the microprogram is the first part of the "channel control" routine]
・A forced branch is made to the answer, and the processing of the "channel control" routine is started. It is assumed that the channel control indicator latch circuit 15 is reset through the reset 1 signal line 27 when the decode circuit 16 decodes the channel control end γ. Therefore, the channel control display latch circuit 15 is in a reset state (displayed during "idle").
When the channel is being controlled, the channel control display signal line 26 lets you know that the CS8 channel control device is in the "Idol j mode", and the microprogram for the "self-diagnosis" routine is written in the CS reading 14 register 12. The "self-diagnosis" routine is processed by sending the "self-diagnosis" routine. Now, during "channel control" or "idle j"
If there is a read failure in S8, it is detected by the check circuit 13, and the DIEC output signal line 22 is excited, so that a new signal arrives through the A8 line 24 and is sent to the request selection circuit 1.
4 through the control request reception signal line 25, and the STL address signal line 31 is set to the CS address 21 through the {W-q line 23, Forcibly branches to "Processing" Roujin. At this time, when the CS 8 learns from the channel control indication signal line 26 that the channel control unit 4 is in the "idle" state, the CS 8 "sends a microinstruction to handle the failure during idle control to the CS read register 12. At this time, the state of the hardware constituting the channel control unit 4 and the
(Information for microprogramming and controlling the hardware that makes up channels 5 to 7; specifically, the contents of memory tables, data, and registers for firmware in the CS) condition and
The execution trajectory of the microprogram that controls the hardware constituting channels 5 to 7 is extracted, the cause and range of the failure are analyzed, and the optimal channel number to be used for reporting the failure to the central processing unit 1 is determined. is selected, and further processing is performed to report the failure to the central processing unit 1 using the channel number.

If such an operation completes the fault processing and returns to the idle state, and even if the routine detects a fault again, it will not send a fault detection report to the central processing unit 1 unless another control request occurs. It will not be done.

〔Effect of the invention〕

As explained above, the present invention provides a method for controlling a plurality of channel devices in a time-sharing manner when a channel control device that controls a plurality of channel devices detects a fault in the channel control device in a state where it is not connected to any channel device. By reporting to Extracts the execution trajectory of the microprogram that controls the constituent hardware, analyzes the cause and scope of the failure that has occurred, and selects the optimal channel number to be used for reporting the failure to the central processing unit. Furthermore, by reporting a failure to the central processing unit using the channel number, it is possible to identify the channel device in which the failure has occurred and to ensure failure recovery processing.

[Brief explanation of the drawing]

FIG. 1 is a connection configuration diagram of the human output channel targeted by the present invention, FIGS. 2 and 3 are flowcharts of the processing of the microprogram in the channel control unit 4, and FIG. 4 is a diagram of the present invention. FIG. 2 is a block diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Central processing unit, 2... Human output processing device, 3... Human output device, 4... Channel control unit, 5, 6.7... Channel, 8... Control storage , 9... Human output interface, 10... Channel interface, 11... I/O interface, 12... CS readout register, 13... Check circuit, 14... Request selection circuit, 5 ...Channel control display latch circuit, 6...Tecode circuit, j...CS address register, 0, 23. 24 -...I word- line, 2...
・Check output A Δ line, 5... Control request reception signal line, 6... Channel control display signal line, 7... Reset 1/A J1- line, 0... BT address signal line, 1 ...STL addressing line. Patent applicant 1” Hondenki Co., Ltd.

Claims (1)

[Claims] 1. A method for handling a failure detected by a channel control device that controls a plurality of channel devices in a time-sharing manner, wherein the channel control device does not control any specific channel device;
When a failure is detected in the channel control device while searching for a control request from the channel device or a startup instruction for the channel device from the central processing unit,
Temporarily suspends reporting the failure to the central processing unit,
When a control request from a channel device or a startup instruction for a channel device is received from the central processing unit, the hold is released, and after the operation request to the channel control device is forcibly terminated, the state of the installed hardware constituting the channel control device;
The state of control information used when controlling the channel device,
By extracting the execution trajectory of the microprogram that controls the hardware that makes up the channel device and analyzing the cause and scope of the failure that has occurred, we can determine the optimal channel to use when reporting the failure to the central processing unit. A fault handling method for a channel control device, which selects a channel number and reports a fault to a central processing unit using the selected channel number.