JPH0337739A - Microprogram controller - Google Patents

Abstract

PURPOSE:To eliminate the need of change of a program for analyzing a fault by sending out an error code corresponding to a fault part of HW (hardware) by a micro-instruction, in the case of a discrepancy for a processing which can be decided to be caused by a fault of the HW in the course of operation of a microprogram. CONSTITUTION:When a micro-instruction (SEC instruction) is sent out to a read-out register 102 from a control storage 101, an instruction field is decoded by an instruction decoder 103, and an F/F 104 for informing a fault is set. Also, an error code existing in a constant field in the micro-instruction in the read-out register 102 is set to an error code holding register 105. As a result, its own device comes to a fault state and the generation of a fault is informed to a diagnostic device 200. The diagnostic device 200 sends out the contents of the error code holding register 105, that is, an error code by a sending-out circuit 106, and also, executes a logout for reading out internal data of a fault device. In such a way, it is unnecessary to change a program for analyzing a fault in the diagnostic device 200.

Description

TECHNICAL FIELD The present invention relates to a microprogram control device, and more particularly to failure analysis when a failure is detected in the operation of a microprogram.

BACKGROUND ART Conventionally, in a microprogram control device, when a processing inconsistency that can be determined to be caused by a hardware (hereinafter abbreviated as HW) failure during microprogram operation is detected, the device itself is placed in a failure state. Then, a report is sent to a diagnostic device, a failure analysis is performed based on the stop address, and the location of the HW failure is pointed out.

For example, when an interrupt occurs, detailed information on the cause of the interrupt is generally read in the process of processing the interrupt, and the cause is determined. At this time, it is impossible that there is no cause for interrupt. In other words, there is a contradiction, and in this case, there may be a failure in the interrupt control circuit or the interrupt cause detail flag.

Then, the device itself is brought to a halt state, and its halt address is reported to the diagnostic device.

The diagnostic device has a fault analysis program, and the fault is analyzed using the program. A well-known program is one that traces the sequence backwards from the input stop address and points out the location of the failure.

However, although the above-mentioned conventional microprogram control device performs failure analysis based on the stop address, the address of the microinstruction that sets the own device in a failure state is changed due to microprogram modification, microprogram assembly, etc. Sometimes. In such a case, it is necessary to change the program for failure analysis using microinstruction addresses. In other words, the conventional fault analysis method has the disadvantage of not being flexible when changing the address of a microinstruction.

OBJECTS OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional drawbacks, and its purpose is to provide a microprogram that can flexibly respond to changes in the address of microinstructions and that can effectively analyze failures. The purpose of the present invention is to provide a control device.

Composition of the Invention A microprogram control device according to the present invention is a microprogram control device that executes a predetermined process in response to a microinstruction read from a control memory, and the microprogram control device executes a predetermined process in response to a microinstruction read out from a control memory. A control memory TA that stores a microinstruction that sends out an error code to identify a fault location that is likely to cause a fault, and a fault that corresponds to the error code in response to the sending of the error code. The present invention is characterized in that it has a fault information sending means for sending information regarding a fault location that is a cause of the occurrence of the problem.

Example Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of a microprogram control device according to the present invention.

In the figure, a microprogram control device i00 according to an embodiment of the present invention includes a control memory 101 in which a microprogram is stored, a read register 102 that stores microinstructions read from the control memory lOI, and a microprogram controller i00 in which a microprogram is read out. an instruction decoder 103 that decodes instructions;
It is configured to include a flip-flop (F/F) 104, an error code holding register 105 that holds an error code, and a sending circuit 10B that reports the contents of the error code holding register 105 to the diagnostic device 200. Note that 20G is a diagnostic device.

The microprogram in control memory 101 is configured to include a plurality of microinstructions. In addition to the microinstruction for executing the original processing, the microinstruction includes a microinstruction (hereinafter referred to as SEC instruction) that notifies the device itself of a failure and also sets an error code corresponding to the failure in the error code holding register 105. ) is included.

When the microprogram detects a processing inconsistency that is determined to be caused by a HW failure, the F/F 104 issues an SEC command to put its own device in a failure state, and also notifies the diagnostic device 200 that it is in a failure state. This is set when notifying.

A well-known fault content recovery means is used in the sending circuit 10B. This is shown in FIG.
6, and outputs the contents of the error code holding register 1.5, stop address holding register LO8, status information holding register 107, etc. in the microprogram control device 100 in response to the select signal 20 from the diagnostic device 200. 21. Alternatively, a well-known scan path may be used to collect the failure details.

Next, microinstructions in control memory 101 will be explained. FIG. 2 is a conceptual diagram showing one format of microinstructions in a microprogram control device according to an embodiment of the present invention. In the same figure (a), each microinstruction in the control memory consists of a branch field 201 that generates the address of the next microinstruction, an @instruction field 202 that gives a control instruction, and a constant field 203 that stores constants. It is configured.

If the microinstruction is the above-mentioned SEC instruction, the branch field 201 contains the branch instruction, the control instruction field 202 contains the SEC instruction, and the constant field 2, as shown in FIG.
The error code will be set in 03 respectively.

Further, the error code is determined in advance in accordance with the expected failure location, as shown in FIG. For example, an error code is assigned to all expected failures, such as the error code -'00'' in the case of a hardware failure of the interrupt control circuit or interrupt cause detail flag mentioned above.

Then, for the part of the microprogram sequence in the control memory where it is predicted that a failure will occur,
It is sufficient to store in advance an SEC instruction including an error code of a predicted failure location in case an error occurs in that part. At the same time, by storing a fault location identification table as shown in Figure 4 in the diagnostic device, the fault location within the microprogram control device can be determined by referring to the error code sent from the sending circuit. This makes it easy to point out. In other words, instead of the conventionally used program that analyzes failures based on stop addresses, a program that analyzes failures based on error codes can be provided in the diagnostic device.

Returning to FIG. 1, in the microprogram control device having such a configuration, during microprogram processing, for example, when determining the state of HW, a state or combination of states that is impossible on the logic circuit or in the processing of the microprogram is detected. It is thought that this was due to some kind of HW defection,
Depending on the detected contents and the processing process of the microprogram,
It may be possible to limit the location of the failure. In such a case,
As mentioned above, an SEC command with an error code set to identify the failure location of the HW is stored in the control memory in advance, and the microprogram issues the SEC command when a discrepancy is detected. Just do it like this.

When the SEC instruction is sent from the control storage lot to the read register 102, the instruction field shown in FIG. 2 is decoded by the instruction decoder 103, and the F/F 104 for fault notification is
Set. Along with that, 1. The error code existing in the constant field of the microinstruction in the read register 102 is set in the error code holding register 105.

As a result, the own device becomes in a failure state and the diagnosis device 200 is notified of the occurrence of the failure.

The diagnostic device 200 uses the sending circuit 10B to send out the contents of the error code holding register 105, that is, the error code, and performs logout by reading the internal data of the faulty device. Further, the diagnostic device 200 activates a program for failure analysis in a case where a HW inconsistency is detected by the microprogram and becomes a failure. When the fault analysis program is executed, the location of HW damage can be identified by referring to the error code and the above-mentioned fault location table.

In other words, even if the address of a microinstruction is changed due to a modification of the microprogram, the specified error code can be used as is, so there is no need to make any changes to the fault analysis program in the diagnostic device. .

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, when a processing inconsistency that can be determined to be caused by a HW failure is detected during microprogram operation, an error code corresponding to the failed part of the HW is sent by a microinstruction. Therefore, there is no need to change the program for failure analysis, it is possible to flexibly respond to changes in microinstruction addresses, and failure analysis can be performed effectively.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a microprogram control device according to an embodiment of the present invention, FIG. 2 is a conceptual diagram showing the configuration of microinstructions in a control memory, and FIG. 3 is an example of the sending circuit in FIG. 1. Figure 4 is a conceptual diagram showing an example of a failure point indication table. Explanation of symbols of main parts 101...Control memory 103...Instruction decoder 105...Error code holding register 200...Diagnostic device

Claims (1)

[Claims] (1) A microprogram control device that executes a predetermined process in response to a microinstruction read from a control memory, and the cause of a failure that is thought to occur during execution of the process in accordance with the microinstruction. a control memory storing a microinstruction that sends out an error code to identify a fault location; and a control memory storing a microinstruction that sends out an error code to identify a fault location; 1. A microprogram control device comprising: fault information sending means for sending out failure information.