JPH06309245A - Scsi interface system device - Google Patents

Abstract

PURPOSE:To detect abnormality when peripheral equipment is executing an instruction from a host side so as to enable, the host side to detect immediately an error state when the error end is executed without setting a check condition by providing a host computor with a means for recognizing massage data as error information detected by a peripheral information device when the message data is received. CONSTITUTION:In a step #11, a host computer transmits command data by a command phase to a peripheral information device. In a step #13, whether a SCSI phase after the command phase is a message in phase or not is decided, and in the case of the message-in-phase, message data is received from the peripheral information device by advancing to a step #14. When this message data is a sense data massage, the received message data is converted to error information by advancing to a step #16, and by confirming the error detected by the peripheral equipment side, the processing flow is finished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a SCSI device suitable for use in a system in which a disk device is connected to an initiator, a host computer or the like using a SCSI device.
Related to the interface system device, in particular, when the peripheral information device detects an error during execution of an instruction from an arbitrary host computer and ends abnormally without setting a check condition, the host computer immediately detects an error state. The present invention relates to a SCSI interface system device made possible.

[0002]

2. Description of the Related Art Conventionally, a computer peripheral information device,
For example, a small computer peripheral device such as a printer device, a scanner device, a magnetic disk device, or an optical disk device is provided with a SCSI device (Small Computer System Syster Interface).
ace) is used, and a system with a host computer is configured through this SCSI device. SCS used for host computers and peripheral information devices
I device is connected by a common cable (SCSI bus)
Up to 8 units can be connected in a daisy chain. Here, a connection example of a system configuration including a conventional host computer using a SCSI device and peripheral devices will be described.

FIG. 5 is a functional block diagram showing an example of a system configuration of a SCSI interface consisting of a conventional host computer and peripheral information device.
In the figure, 1 is a host computer and 1a is its S
CSI controller, 2 is an optical disk device, 2a is its SCSI controller, 3 is a hard disk device, 3
a is its SCSI controller, 4 is a printer, and 4a
Indicates its SCSI controller, and 5 indicates a SCSI bus.

The host computer 1 uses the check condition status sent from the optical disk device 2, the hard disk device 3, the printer 4, etc., which are peripheral information devices, to request sense (REQUEST SEN).
SE) command is issued. This command returns the previous S
It is a SCSI command that confirms error information of the CSI command.

However, in some cases, when the peripheral information device (2-4) detects the occurrence of an abnormal state, the SCSI command processing is terminated without returning the check condition. In such a case, the host computer 1 cannot know the abnormal state detected on the peripheral information device (2-4) side.

That is, the request sense command is sent by the host computer 1 to the peripheral information devices (2-4).
S for obtaining (pruning) the error information detected by
It is a CSI command. And the peripheral information device is SC
When an abnormality is detected during execution of the SI command, a check condition (SCSI status) is set.

At this time, the host computer 1 issues a request sense command to the peripheral information device (2-
The contents (eg, SCSI error information, H / W error information, media error information, etc.) are confirmed by the sense data returned from 4). For example, when a SCSI bus communication error is detected on the peripheral information device (2-4) side, the SCSI phase in which the error is detected is executed again.

Then, in the re-executed SCSI phase, when a SCSI bus communication error occurs, sense data is set without setting a check condition and the SCSI command processing is terminated, which is a general processing method. Is. Therefore, in this case, SC
Immediate SCSI without generating SI status phase
Transition to the bus-free phase.

Next, when a SCSI command other than the request sense command (for example, an instruction to set information recording, information reproduction, recording / reproduction mode, etc.) is received, the peripheral information device executes the SCSI command. Therefore, the sense data is cleared and new sense data is set. Here, the SCSI phase sequence in the SCSI interface system device will be described with reference to the drawings.

FIG. 6 is a diagram showing a normal SCSI phase sequence for the SCSI interface system device shown in FIG. In the figure, P1 to P8 indicate the SCSI phase.

In FIG. 6, when the information recording command is issued, that is, when the SCSI write command is sent, the SC
The sequence of the SI phase is shown. In phase P1, the arbitration phase is entered.
This phase P1 is a phase in which an arbitrary host computer competes with another host computer for the exclusive right of the SCSI bus.

In phase P2, the selection phase is entered. Phase P2 is a phase in which the host computer selects a peripheral information device to use. In phase P3, the process moves to the message out phase. Phase P3 is a phase for sending an identify message.

In phase P4, the command phase is entered. Phase P4 is a phase in which the host computer sends a command to the other peripheral information device. In phase P5, the data phase is entered. Phase P5 is a phase in which reproduction data, recording data, etc. are transferred.

In phase P6, the status phase is entered. Phase P6 is a phase for sending the execution result of the instruction from the host computer. Phase P7
Then, move to the message in phase. This phase P7 is a phase in which information is transferred between the host computer and the peripheral information devices (2-4 in FIG. 5) when the command ends or when it is desired to temporarily disconnect the connection with the SCSI bus. .

In phase P8, the bus free phase is entered. Phase P8 is a phase in which no connection is made with the SCSI bus, and no communication is being performed on the SCSI bus. The above is an example of the sequence of the normal SCSI phase when the SCSI write command is transmitted.

Next, the phase sequence when an abnormality occurs will be described. Here, as an example, in the SCSI phase sequence of FIG. 6 described above, in the command phase P4, a SCSI bus communication error (a parity error occurs due to a defective SCSI cable or electrical noise, and information communication on the SCSI bus is performed). The SCSI phase sequence will be described in the case where an error (which is not performed normally) occurs. An example of a SCSI bus parity error will be described as the SCSI bus communication error.

FIG. 7 shows the SC in the command phase.
It is a figure which shows an example of the SCSI phase sequence when a SI bus communication error generate | occur | produces. P1 to P in the figure
Reference numeral 8 indicates a SCSI phase corresponding to P1 to P8 in FIG. 7, P41 and P42 indicate a command phase, and P71 indicates a message in phase.

It is assumed that a parity error (SCSI bus communication error) occurs in the command phase P41 during the execution of the SCSI phase sequence shown in FIG. In this case, a disk device (for example, FIG.
The optical disc device 2) of the
1 and restore the restore pointers (RESTORE POI) to the host computer (1 in FIG. 5).
NTERS) message is sent.

After that, the process shifts to the command phase P42 again, and the command (SCSI command) from the host computer is received. In this command phase P42,
When the command data or the parity error is detected, the optical disk device detects the sense data (error code: SCSI INTERFACE PARI).
(TY ERROR) is set in the memory, and the process immediately shifts to the bus free phase P8.

As described above, even if the disk device, which is the peripheral information device, is in an abnormal state, the disk device does not transmit the check condition status to the host computer. Therefore, since the host computer has not detected the check condition status, it sends a request sense (REQUES) to the disk device.
TSENSE) command cannot be issued.

As described above, in the peripheral information device,
When the SCSI bus communication error is detected, the check condition is not established, and therefore the host computer cannot send the request sense command to the peripheral information device. Therefore, the host computer executes the next process without knowing the error state, and the peripheral information device re-executes the SCSI phase many times, resulting in a wasteful processing time. There was (the prior art for the inventions of claims 1 to 3).

Further, for example, in an environment in which a SCSI bus communication error is likely to occur due to a defective SCSI cable or the like, the host computer cannot know this state, so there is also a problem that a defective SCSI cable or the like cannot be known. (Prior art to the invention of claim 4).
In this case, the peripheral information device is the initiator (command: S
CSI command output device), the host computer becomes a target (command: device that receives and executes SCSI commands), and peripheral information devices issue SCSI commands and host error information, contrary to normal operation. Such inconvenience can be avoided by means of transferring to a computer.

However, it is general that the peripheral information device is used in the target mode and the host computer is used in the initiator mode. If the host computer does not have the target mode, the peripheral information device cannot issue the SCSI command to transfer the error information to the host computer.

As described above, in the conventional SCSI interface system device, that is, in the system of the SCSI interface composed of the host computer and the peripheral information device, for example, when the SCSI bus communication error occurs, the check condition is not established. The general processing method is to set the sense data and terminate the SCSI command processing, and there is a disadvantage that the host computer cannot know the error status of the disk device. Further, in a device in which the host computer does not have the target mode, the peripheral information device cannot issue the SCSI command to transfer the error information to the host computer.

[0025]

SUMMARY OF THE INVENTION The present invention solves such an inconvenience in a conventional SCSI interface system device composed of a host computer and a peripheral information device, and an error occurs on the peripheral information device side such as a disk device. In this case, in the phase sequence of the SCSI command issued by the host computer next time, in the message-in phase, the sense data is transferred to the host computer so that the host computer can recognize the error state. The first purpose is to provide. Further, even if the host computer does not have the target mode, the peripheral information device can recognize the error state on the host computer side by providing the host computer with means for always reporting the error information when the error state occurs. A second object is to provide a SCSI interface system device as described above.

[0026]

According to the present invention, firstly,
In a SCSI interface system including at least one host computer and a peripheral information device connected to the host computer through a SCSI bus, the peripheral information device detects an abnormality while executing a command from an arbitrary host computer. However, when the processing ends in an error without setting a check condition, the next command from the same host computer determines whether the next command is an error information transmission request command, and the command is a command other than the error information transmission request command. Then, a peripheral information device comprising storage means for storing error information in the message data transferred to the host computer in the SCSI message in phase, and transmission means for transmitting the message data to the host computer. And the relevant message day When receiving, the host computer that the message data is Explore apparatus comprising recognizing means as error information detected, and a capital S
CSI interface system device.

Secondly, there is provided a peripheral information device in the first SCSI interface system, which comprises means for converting error information into SCSI message data and means for transmitting the message data to a host computer.

Thirdly, the host computer in the first SCSI interface system is provided with means for receiving the message data from the peripheral information device and means for converting the message data into error information.

Fourthly, in the first SCSI interface system, after receiving and analyzing the message data (error information), it is determined whether or not the instruction is in the executable SCSI bus state. And a means for transferring to the peripheral information device an execution stop request of the instruction as message data in the SCSI message out phase when the instruction cannot be executed.

[0030]

According to the present invention, when the peripheral information device detects an abnormality during execution of a command (SCSI command) from an arbitrary host computer and ends in error without setting a check condition (error information is set in the device). However, S does not move to the SCSI status phase
When transitioning to the CSI bus free phase), the next command (SCSI command) from the same host computer
Is an error information transmission request command (request sense command), and an instruction determining means for determining whether the command is a command other than the error information transmission request command,
Peripheral information device including storage means for storing error information in message data transferred to the host computer in the SCSI message in phase, and transmission means for transmitting the message data to the host computer, and the message data And a host computer having means for recognizing the message data as error information detected by the peripheral information device when the message is received, the host computer can immediately detect the error state of the peripheral information device. (The invention of claim 1).

Second, the error information is sent to the peripheral information device as S
Means for converting into CSI message data, and transmitting means for transmitting the message data to the host computer,
Similarly, the provision of and makes it possible to immediately notify the host computer of the error state of the peripheral information device (the invention of claim 2). Thirdly, by providing the host computer with means for receiving the message data from the peripheral information device and means for converting the message data into error information, the host computer immediately receives the peripheral information through the SCSI bus. The error state of the device can be known (claim 3).
Invention). Fourth, the host computer receives the message data (error information), analyzes it, and then determines whether or not the instruction is in an executable SCSI bus state, and when the instruction cannot be executed. , Means for transferring the execution stop request of the instruction as message data in the SCSI message out phase to the peripheral information device, thereby eliminating wasteful re-execution of the SCSI phase generated in an unstable SCSI bus state. Time is avoided (the invention of claim 4).

[0032]

First Embodiment Next, a SCSI interface system device of the present invention will be described in detail with reference to the drawings. This embodiment corresponds to the invention of claim 1, but is also related to the inventions of claims 2 to 4. The hardware configuration of the SCSI interface system device of the present invention is the same as that of FIG. 5 described as the conventional example.

FIG. 1 is a flow chart showing the main processing flow at the time of transmitting a sense data message on the disk device side in the SCSI interface system device of the present invention. In the figure, # 1 to # 7 indicate steps.

In step # 1, the command phase (see FIG.
Set P4). In the next step # 2, command data reception processing is performed.

At step # 3, it is determined whether the received command is a request sense (REQUESTSENSE) command. If the command is a request sense command, go to step # 4,
The request sense command processing routine is called to execute the processing, and the flow of FIG. 1 ends.

If the command is other than the request sense command, the process proceeds to step # 5 to set the message in phase (P71 in FIG. 7). Step # 6
Then, the sense data is converted into message data (hereinafter referred to as sense data message) and transmitted.

At step # 7, the SCSI command is processed and the flow of FIG. 1 is terminated. Through the above steps # 1 to # 7, the process at the time of transmitting the sense data message on the disk device side is executed, and the host computer side can recognize the error state generated on the peripheral information device side such as the disk device. it can.

An example of the sense data message used in the SCSI interface system device of the present invention will be described.

FIG. 2 is a diagram showing an example of a specific configuration of the sense data message used in the SCSI interface system device of the present invention.

The sense data message shown in FIG. 2 is composed of 6 bytes as one of the extension messages. That is, the byte has a 6-byte structure of 0-5. And the data of byte 0 is "01",
The ID indicating the extension message and the data of byte 1 are "0
"A" is an ID indicating the sense data message, byte 2
Data is “03”, which indicates the number of subsequent bytes.

Further, the data of byte 3 is “α”, which indicates a sense key (a large classification of error information), the data of byte 4 is “β”, which indicates a sense code (content of error), and the data of byte 5 is The data is “γ” and indicates sense code qualification (details of error content). When an error occurs, the peripheral information device side transfers a sense data message indicating such a content to the host computer, and then the peripheral information device continues processing the command (step # 7 in FIG. 1).

The above operation is the processing at the time of transmitting the sense data message on the side of the peripheral information device. Next, a process when the sense data message is received on the host computer side will be described with a flow.

FIG. 3 is a flow chart showing the main processing flow when the host computer side receives a sense data message in the SCSI interface system device of the present invention. In the figure, # 11- #
Reference numeral 17 indicates a step.

At step # 11, the host computer transmits command data to the peripheral information device in the command phase. In step # 12, the SCSI phase converted by the peripheral information device is monitored.

At the next step # 13, it is determined whether the SCSI phase after the command phase is the message in phase. If it is in the message in phase, the process proceeds to step # 14 to receive the message data from the peripheral information device.

At step # 15, it is determined whether the message data is a sense data message.
If it is a sense data message, step # 1
6, the received message data is converted into error information, the error information detected on the peripheral information device side is confirmed, and the flow of FIG. 3 is ended.

On the other hand, as a result of the judgment at the previous step # 13, when the SCSI phase after the command phase is not the message in phase, and as a result of judgment at the step # 15, it is not the sense data message, Go to step # 17. In step # 17,
According to the SCSI phase that is switched on the peripheral information device side,
Continue processing the SCSI command.

Through the above-described steps # 11 to # 17, the processing when the sense data message is received on the host computer side is executed, and the content of the error that has occurred on the peripheral information device side can be recognized (step #
16). By the way, according to the SCSI standard (ANSI),
If the peripheral information device (target) has the right to switch the SCSI phase and the host computer wants to notify the peripheral information device of the abnormality immediately,
Assert the SI attention signal ".

In this case, the peripheral information device is
After confirming that the SI attention signal is asserted, it is necessary to shift to the message out phase (P3 in FIG. 6). Next, a process to be performed on the host computer side after checking the content of the sense data message will be described with reference to a flow.

FIG. 4 is a flow chart showing the main processing flow of the SCSI interface system device of the present invention after confirming the contents of the sense data message on the host computer side. In the figure, # 21
~ # 27 indicate steps.

At step # 21, the host computer confirms the content of the sense data message. In the next step # 22, it is determined whether the content is an abnormality of the SCSI bus.

If the SCSI bus is abnormal, the process proceeds to step # 23 to assert the SCSI attention signal to the peripheral information device. When the peripheral information device detects that it has switched to the message out phase in step # 24, an abort message is transmitted to the peripheral information device in the next step # 25.

This abort message is an option message of the SCSI standard, and the peripheral information device receiving this message immediately terminates the SCSI command processing, and the SCSI bus free phase (P8 in FIG. 6).
It is supposed to move to. Therefore,
Proceeding to step # 26, the SCSI command processing is terminated and the flow of FIG. 4 is terminated.

On the other hand, as a result of the judgment in the previous step # 22, if the SCSI bus is not abnormal, the process proceeds to step # 27 to perform the next phase process. afterwards,
In step # 26, the SCSI command processing is completed,
The flow of FIG. 4 is terminated.

By the above-described processing of steps # 21 to # 27, the processing after confirming the content of the sense data message on the host computer side is executed. Generally, SC
Once an SI bus abnormality (SCSI bus parity error) occurs, there is a high probability that it will occur in the future.

In the SCSI interface system device of the present invention, when a SCSI bus parity error occurs, the host computer side suspends the SCSI command processing (step # 26), so that an error that is likely to occur after that occurs. The unnecessary processing time on the resulting SCSI is avoided, and the SCSI
It can also notify you of abnormal bus conditions. Therefore,
A system that is significantly more efficient than conventional devices is obtained.

[0057]

According to the SCSI interface system device of claim 1, while the peripheral information device is executing a command (SCSI command) from an arbitrary host computer,
When an abnormality is detected and the process ends in error without setting a check condition, the host computer can immediately detect the error state of the peripheral information device. Therefore, quick and appropriate processing for the error can be performed, and the processing efficiency of the system is improved.

According to the SCSI interface system device of claim 2, since the error information is converted into a SCSI message and transmitted in the SCSI interface system device of claim 1 described above,
Through the bus, the error state of the peripheral information device can be immediately notified to the host computer. Therefore,
Similar to the SCSI interface system device according to the first aspect of the present invention, quick and appropriate processing corresponding to the error is possible, and the processing efficiency of the system is improved.

According to the SCSI interface system device of claim 3, in the SCSI interface system device of claim 1, the host computer is capable of converting the received SCSI message data into error information. Therefore, similarly to the SCSI interface system device according to claim 1 or 2, the host computer can immediately know the error state of the peripheral information device through the SCSI bus, and can quickly and appropriately process the error. Therefore, the processing efficiency of the system is improved.

In the SCSI interface system device according to claim 4, in the SCSI interface system device according to claim 1, the host computer can execute the command after receiving and analyzing the SCSI message data (error information). It is determined whether the status is the SCSI bus state, and if the relevant instruction cannot be executed, a request to cancel the execution of the relevant instruction can be transferred to the peripheral information device as message data in the SCSI message out phase. I have to. Therefore, SCSI that occurs in an unstable SCSI bus state
The wasteful time required for re-execution of the phase is avoided, and the processing efficiency of the system is significantly improved.

[Brief description of drawings]

FIG. 1 is a flow chart showing a main processing flow at the time of transmitting a sense data message on a disk device side in a SCSI interface system device of the present invention.

FIG. 2 is a diagram showing an example of a specific configuration of a sense data message used in the SCSI interface system device of the present invention.

FIG. 3 is a flowchart showing a main processing flow when a sense data message is received on the host computer side in the SCSI interface system device of the present invention.

FIG. 4 is a flowchart showing a main processing flow after confirming the contents of the sense data message on the host computer side in the SCSI interface system device of the present invention.

FIG. 5 is a functional block diagram showing an example of a system configuration of a SCSI interface including a conventional host computer and peripheral information devices.

FIG. 6 is a diagram showing a normal SCSI phase sequence for the SCSI interface system device shown in FIG.

FIG. 7 is a diagram showing an example of a SCSI phase sequence when a SCSI bus communication error occurs in the command phase.

[Explanation of symbols]

 1 Host Computer 1a SCSI Controller 2 Optical Disk Device 2a SCSI Controller 3 Hard Disk Device 3a SCSI Controller 4 Printer 4a SCSI Controller 5 SCSI Bus

Claims (4)

[Claims] 1. A SCSI interface system comprising at least one host computer and a peripheral information device connected to the host computer via a SCSI bus, the peripheral information device executing an instruction from an arbitrary host computer. In addition, when an error is detected and the processing ends in an error without setting a check condition, the next instruction from the same host computer is an instruction determining means for determining whether or not the instruction is an error information transmission request instruction, and the instruction transmits error information. A storage unit for storing error information in the message data transferred to the host computer in the SCSI message in phase when the command is other than the request command, and a transmission unit for transmitting the message data to the host computer. Peripheral information device and When receiving the message data, SCSI interface system apparatus characterized by being composed of a host computer, the capital of the message data Explore apparatus comprising recognizing means as error information detected. 2. The peripheral information device according to claim 1, further comprising: a means for converting error information into SCSI message data, and a transmitting means for transmitting the message data to a host computer. . 3. The SCSI interface system according to claim 1, further comprising means for receiving the message data from a peripheral information device and means for converting the message data into error information. 4. The SCSI interface system according to claim 1, wherein after the message data (error information) is received and analyzed, a means for determining whether or not the instruction is in an executable SCSI bus state, and the instruction. And a means for transferring the execution stop request of the instruction to the peripheral information device as message data in the SCSI message out phase when the above is impossible to execute.