JP2000339268A - Scsi host adapter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To store information on a SCSI(Small Computer System Interface device at the time of starting a system by fetching instruction/transfer data from a device main body via a host local bus in an information processor and transferring data from a host control part to the SCSI device. SOLUTION: A host bus control part 12 controls the connection between the host local bus 5 of an information processor main body and a SCSI host adapter 1. Then, instruction/transfer data from the information processor main body is fetched into the adapter 1 with the timing of the bus 5. An instruction and data transferred from the part 12 are transferred to a SCSI bus control part 13 to execute data transfer with a SCSI device connected through a SCSI bus 6 corresponding to the protocol of a SCSI. Thus, after starting the system of the information processor, a data transferring rate set between respective SCSI devices connected with the adapter 1 can be confirmed by an operator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a SCSI host adapter, and more particularly to an information processing system in which an information processing apparatus main body and various peripheral devices (for example, a file device, a disk device, a tape device, etc.) are connected by a SCSI bus. The present invention relates to a SCSI host adapter that displays a transfer rate, device-specific information, and the like determined with each connected SCSI device.

[0002]

2. Description of the Related Art SCSI (Small Compute)
r System Interface is a hard disk (HDD), CD, or the like for an information processing device such as a personal computer (hereinafter, referred to as a PC) or a workstation.
-An interface standard for connecting and using peripheral devices such as a ROM drive and a magneto-optical disk drive (MO). Currently, there are three types of standards for SCSI.

First, SCSI-1 is a basic standard, and has a maximum transfer speed of 4 MB / sec. However, some of the standards were ambiguous, and because of the incorporation of manufacturer-specific technology, it was not always possible to use products from two different companies at the same time (it was not completely compatible). Therefore, SCSI-2 was born as an upward compatible standard of SCSI-1, and this standard is currently most widely adopted. SCSI-2 further includes Fast-SCSI and Wi-Fi.
Two types of standards, de-SCSI, are prepared.
These two standards mainly relate to a data transfer method, and
-In SCSI, data is transferred in 8-bit width, and
In e-SCSI, data is transferred with a 16-bit width. The transfer rate is 10 MB / sec at maximum in Fast-SCSI, and 20 MB / sec at maximum in Wide-SCSI. Furthermore, the latest standard, SCSI-3, is currently being formulated, and this standard will provide various enhancements such as further speedup and multitasking.
Among them, the transfer speed is twice that of SCSI-2, and Fa
The standard called st20 (or Ultra-SCSI) has also been standardized, and currently compatible SCSI devices are commercialized.

FIG. 10 shows a configuration diagram of a general SCSI system. This SCSI interface is SCSI
The host adapter 80 is included. The SCSI host adapter 80 includes a SCSI control unit 80a and a BIOS-ROM.
80b. Control unit 80a of host adapter 80
Are connected to a local bus (PCI bus) 85 in the PC and to a SCSI device 82a via a SCSI flat cable 84 in the main unit. Also,
The control unit 80a is daisy-chain connected to a plurality of SCSI devices 82b to 82g via a SCSI cable 81. Also, the SCSI devices 82a and 82a
The connector not connected to the other SCSI device g is connected to the terminators 83a and 83b, and electrically connects the SCSI cables 81 and 84.

The SCSI host adapter 80 and each SCS
The data transfer method and transfer speed between the I devices 82a to 82g are determined at the time of the initialization processing of the SCSI host adapter 80. The transfer rate determined for each SCSI device 82 is set by the SCSI controller 80a in the SCSI host adapter 80. Thereafter, data transfer is performed with the set value. That is, a unique ID is given to each of the SCSI devices 82a to 82g and the SCSI host adapter 80, and this ID (transfer partner)
The SCSI host adapter 80 performs data transfer at each speed. Note that the SCSI host adapter 80 is assigned ID = 7.

The transfer rate on the SCSI bus is Fast1
The transfer at a maximum of 10 MB / s at 0 and the high-speed transfer at a maximum of 20 MB / s in Fast 20 can be realized only when the transfer method is synchronous transfer. That is, at the time of asynchronous transfer, a maximum of 5 MB is used for both Fast10 and Fast20.
/ Sec (up to 10 MB / sec in Wide-SCSI).

The execution of the transfer rate Negotiation determination protocol is performed during the initialization processing of the SCSI host adapter 80 which is performed when the information processing apparatus is started. FIG. 11 shows a flow chart of a series of operations of the conventional SCSI host adapter initialization.

In step 91, the reset input to the SCSI host adapter 80 initiates the initialization of the SCSI controller (controller) 80a. S at step 92
Initialize the CSI bus. This stops each SCSI device 82 connected at that time from driving (using) the signal line, and shifts the phase (a certain processing state being processed) of each SCSI device 82 to the initial state. It also serves as a process to make it work. A state where all the SCSI devices do not use the bus is called a bus free. In step 93, it is confirmed that the SCSI bus is in the bus free state, and the host adapter 80 checks the ID (=
7) The target to be selected is the I of the SCSI device 82.
The signal line corresponding to D (one of 0 to 6 in this example) and the ATN line are asserted (true: low), and the BSY (busy) signal is deasserted (false: high) (selection phase).

Each of the SCSI devices 82a to 82g has
When detecting that its own ID is asserted, BSY
Assert the signal and respond. That is, it notifies the SCSI host adapter 80 that it is present. The SCSI host adapter 80 performs this operation for all IDs. This series of operations is performed by the SCSI command “Test
Unit Ready command ”or the like. In step 94, the feature information (specification information) of the connected SCSI device is extracted from the SCSI device 82 that has been confirmed to be connected in step 93 described above. This information includes a device type, a function level of a supported function, and the like. In this, there is support information of the transfer method, and information on whether or not the synchronous transfer is supported is included.

Next, at step 95, the setting parameters of each SCSI device 82 are set in the SCSI controller 80a. This setting value will be
And the data transfer between the SCSI devices 82. Here, the operation of acquiring the feature information is performed by the SCSI command “Inquire command” or the like. In step 96, various settings relating to the other SCSI control unit 80a are performed, and the initialization ends.

Next, with reference to a flowchart of FIG. 12, a description will be given of a part of setting a data transfer rate (transfer rate) for each SCSI device 82 performed in step 95 of FIG. Here, the S obtained in step 94
The value of the feature information of the CSI device 82 is referred to. An example of the content of this feature information is shown in FIG.
iry data format ".

In step 101, Inquire data is obtained. In step 102, it is determined whether or not the currently targeted SCSI device 82 supports synchronous transfer. This is determined by the value indicated by bit 4 “Sync” of the seventh byte in FIG. 13 described above. When this bit is “1”, it indicates that the SCSI device 82 supports synchronous transfer. If synchronous transfer is not supported, a maximum rate (5 MB / sec) for asynchronous transfer is set in step 105. On the other hand, for the SCSI device 82 supporting the synchronous transfer, the process proceeds to step 103, and shifts to the process of setting the maximum speed in the synchronous transfer mode. This is determined by the exchange between the SCSI host adapter 80 and the SCSI device 82.

The SCSI host adapter 80 starts exchange of a transfer rate determination (ie, transfer negotiation) only with a device for which synchronous transfer support is specified. As a method for this determination, the SCSI host adapter 8
Set the maximum transfer rate at which the 0 side can operate to the connected SCSI
Inquire about the device 82. If the SCSI host adapter 80 is a host adapter that supports Fast10, the rate is 10 MB / sec. On the other hand, the SCSI device 82 side sets a value indicating OK if the operation at the speed presented from the SCSI host adapter 80 is possible, otherwise, the maximum transfer speed that the SCSI device 82 can support. Returns a value indicating

The SCSI host adapter 80
Looking at the return value from the I-device 82,
The data transfer rate for the CSI device 82 is determined. This operation is performed for all the connected SCSI devices 82. Here, the data transfer speed in the Fast 20 is a device 8 designed to be compatible with SCSI-2 because it is newly added in SCSI-3.
There are things that cannot be determined by 2.

Incidentally, in the SCSI system, there is a limitation on the cable length in addition to the transfer speed. That is, there are restrictions on the transfer speed, cable length, and number of connected devices, and if these restrictions are violated, transfer data is not guaranteed. In the worst case, data in the HDD or the like may be destroyed.

Conventionally, this type of initial setting method is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-116349. That is,
Automatically set the relationship between the device and the driver software on the system. Driver software corresponding to each device after system startup is installed. This prior art has means for acquiring information unique to a peripheral device connected to a SCSI bus, adding an attribute used by software to the information, and setting and saving the information as system information. Also,
At the time of system start-up, there is provided a means for comparing with the configuration of the peripheral device connected to the SCSI bus and notifying the user when there is a conflict. Further, when the user program uses a peripheral device connected to the SCSI bus, it is determined whether the user program is used within the range of the system configuration indicated by the system configuration information created as described above. It has means for notifying the user program.

In this prior art, the following is realized by adding the attribute used by software to the unique information of the peripheral device connected to the SCSI bus and setting it as system configuration information.

That is, when starting up the system, it is determined whether or not the configuration of the peripheral device connected on the SCSI bus matches the system configuration indicated by the system configuration information. If they are different, the operator is notified.
Further, it is determined whether or not the processing mode for the peripheral device on the bus by the application program is inconsistent with the processing mode (software attribute) set in the system configuration information. If an error occurs, the program is notified, and if not, the processing is continued.

As described above, when the system is started up, by comparing and checking the peripheral device configured on the bus and the system configuration managed by the software, an erroneous operation due to a change in the system configuration can be prevented. Also,
Data destruction due to program mistakes and operation mistakes is prevented.

[0020]

A first problem is that, in the prior art, after the information processing apparatus is started, an operator judges a data transfer rate set between each SCSI device connected to a SCSI host adapter. That is not possible. The reason is that the individually set transfer rate data is set only in the SCSI control section, and the transfer rate data is not stored in the storage section accessible from the operator (the information processing apparatus main body). .

A second problem is that the SCSI host adapter that supports Ultra transfer always unconditionally sets the maximum transfer speed of the board to 20 MB / sec for SCSI devices that support synchronous transfer. To the device. As a result, although synchronous transfer is supported, it is not compatible with Ultra-SCSI, and Negotiation of 20 MB / sec.
Connecting a SCSI device that cannot respond to
If a SCSI device that does not support Ultra-SCSI but responds to negotiating at 20 MB / sec is connected, a malfunction of the operation will occur. The reason is that, although the cable length and the number of connected devices can be visually confirmed, it is not possible to confirm the transfer speed (Ultra-SCSI environment or not) finally set for each device in the transfer negotiation. is there.

An object of the present invention is to provide an SCS at system startup.
In the initial processing for the I device, the information of the SCSI device connected to the SCSI host adapter is stored in a certain storage unit.

Another object of the present invention is to allow information set in each device to be read from a storage unit in a main system after the system is started.

Still another object of the present invention is to restrict the SCSI-3 standard (in the SCSI mode in the Ultra-SCSI mode).
In order to operate the bus, the cable length should be 1.5 m or less when connecting three or less devices within a cable length of 3 m or four or more devices (seven or less). ) Can be easily confirmed, so that it is possible to prevent data corruption and data corruption due to access to the SCSI device.

[0025]

In order to solve the above-mentioned problems, a SCSI host adapter according to the present invention employs the following characteristic configuration.

(1) A plurality of S connected to the SCSI bus
In a SCSI host adapter for performing a data transfer speed setting process with each of the SCSI devices in a system including a CSI device and an information processing device, a command / transfer data from the information processing device main body is transferred to the information processing device. A host bus control unit that receives data via a host local bus within the host computer, and transmits data from the host bus control unit to a SCSI bus.
The SC via the SCSI bus according to a protocol
A SCSI host adapter comprising: a SCSI bus controller for transferring data to an SI device.

(2) a host bus connector for connecting the host bus control unit and the host local bus;
The S described in (1) above, comprising the SCSI bus control unit and a SCSI bus connector for connecting the SCSI bus.
CSI host adapter.

(3) The SC according to (1), further comprising an externally accessible storage unit for storing a data transfer rate determined between the SCSI host adapter and the SCSI device.
SI host adapter.

(4) The SCSI host adapter according to (3), wherein the storage unit is provided in the information processing apparatus.

(5) The SCSI according to the above (3) or (4), further comprising a display device for reading the individual information data of the plurality of SCSI devices and the value of the data transfer speed written in the storage section and displaying the read data as a table. Host adapter.

(6) The SCSI host adapter according to (1), wherein the SCSI bus control unit includes a SCSI bus terminator for shaping the waveform of the SCSI bus according to the connection form of the SCSI device.

[0032]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the configuration and operation of a preferred embodiment of a SCSI host adapter according to the present invention.
This will be described in detail with reference to FIGS.

FIG. 1 shows a configuration diagram of a system using a SCSI host adapter according to the present invention. This system includes an information processing device 2, a SCSI device 4, and an SC that connects the information processing device 2 and the SCSI device 4.
It is constituted by an SI bus 6. The information processing device 2 uses the SC
It includes an SI host adapter 1, software 3, a host local bus 5 for connecting them, and a setting information storage unit 7. The setting information storage unit 7 stores a data transfer speed value set for each SCSI device 4 and necessary items from the specification information of each SCSI device 4.

Next, FIG. 2 shows a detailed configuration diagram of the SCSI host adapter 1 in FIG. The SCSI host adapter 1 is connected to the information processing device 2 via a host local bus 5. The SCSI device 4 to be connected is
They are connected in a daisy chain manner via the SCSI bus 6. The SCSI host adapter 1 includes a host bus connector 11, a host bus controller 12, a SCSI bus controller (SCSI controller) 13, a SCSI bus terminator 14, a SCSI host adapter control software 15, and a SCSI bus connector 16. In.

The host bus connector 11 is a SCSI
The connection between the host adapter 1 and the host local bus 5 is provided. The SCSI bus connector 16 is an SCS
It is for connection between the I host adapter 1 and the SCSI bus 6. The host bus control unit 12 controls the connection between the host local bus 5 of the information processing apparatus 2 and the SCSI host adapter 1, and transmits commands and transfer data from the information processing apparatus to the SCSI host adapter at the timing of the host local bus 5. Take it into 1.

The command and data passed from the host bus control unit 12 are passed to the SCSI bus control unit 13,
The data is transferred to and from the SCSI device 4 connected via the SCSI bus 6 in accordance with the above protocol. S
The CSI bus termination terminator 14 performs termination control for shaping the waveform of the SCSI bus 6 according to the connection form of the SCSI device 4 connected to the SCSI host adapter 1.

FIG. 3 shows a configuration example of a logical storage table of information stored in the setting information storage unit 7. Where S
This is an example in which the type of a connected device (hard disk, CD-ROM, etc.) and the value of the transfer speed set for the device are stored for each CSI-ID.

Next, the operation of the SCSI host adapter 1 according to the present invention will be described with reference to FIGS. First, the operation of storing the value of the data transfer rate set for each SCSI device 4 and the necessary items obtained from the specification information of each SCSI device 4 in the setting information storage unit 7 will be described.

The initialization processing of the SCSI host adapter 1 is also performed during the initialization processing performed at the time of starting and resetting the information processing apparatus 2 in FIG. The initialization process of the SCSI host adapter 1 is started when the information processing device 2 issues an initialization signal on the host local bus 5. SC
The flow of initialization of the SI host adapter 1 and the connected SCSI device 4 is as follows. The SCSI host adapter control software 1 incorporated in the SCSI host adapter 1 by the initialization signal entered in the SCSI host adapter 1
5, an initialization process is performed.

First, the SCSI bus control unit 13 is initialized. This includes clearing the transfer speed data for each ID. Second, the SCSI bus 6 is initialized. This stops each device 4 connected to the SCSI bus 6 from driving (using) each signal line in the SCSI bus 6, and changes the phase of each device 4 (one processing state being processed). initialize. All SC
The SI device 4 enters the initial state, and the SCSI bus 6 enters the bus free state. Third, check that the SCSI bus 6 is in a bus free state, and select
The process proceeds to the phase and recognizes which ID the SCSI device 4 is connected to.

Next, the device name information (specification information) is sequentially extracted for the IDs whose connection has been confirmed. Based on this information, it is determined whether the target SCSI device 4 supports synchronous transfer, and the process for determining the data transfer speed is started. Here, the determined transfer speed is set in the setting information storage unit 7 at the same time as it is set in the SCSI bus control unit 13.
Written by the CSI host adapter control software 15. In the setting information storage unit 7, information required from the specification information of each connected device in addition to the data transfer speed is stored for each ID. The value set in the SCSI bus control unit 13 will be used for data transfer performed to each SCSI device 4 in the future.

Next, the operation of extracting the stored data by the operator will be described. The operator accesses the setting information storage unit 7 by operating software on the information processing device 2, reads out data for each ID, and outputs the data to the display device, so that the current setting status can be confirmed.

Next, FIG. 4 shows another configuration diagram of a system using the SCSI host adapter according to the present invention, and FIG. 5 shows a specific configuration diagram of the SCSI host adapter in FIG. The information processing device 2 'includes a SCSI host adapter 1', a host local bus 5, a setting utility 3,
1. Application 32, OS (Operating
System) includes a kernel 33 and a device driver 34 for a SCSI host adapter. SCSI
The host adapter 1 'is connected to the host local bus 5 and SC
The SCSI bus 6 is connected to one or more SCSI devices 4.

On the other hand, the SCSI host adapter 1 ′ includes a host bus connector 11 connected to the host local bus 5, a SCSI bus connector 16 connected to the SCSI bus 6, a host bus controller 12, and a SCSI bus controller ( It has a SCSI controller 13, a SCSI bus terminator 14, SCSI host adapter control software 15, and a setting information storage memory 71. The setting information storage memory 71 includes a host bus control unit 12, an SCS
It is connected to the I bus control unit 13 and the SCSI host adapter control software 15. In the following description, a narrow-SCSI having a data bus width of 8 bits will be described. In the Wide-SCSI, the bus width becomes 16 bits, the host ID becomes 15, and the number of connectable SCSI devices 4 becomes 15. .

In the system shown in FIG. 4, the setting information storage unit 7 is realized by hardware on the SCSI host adapter 1 '. The SCSI host adapter 1 'mounted on the information processing device 2' is connected to the information processing device 2 'by a host local bus 5. Also, the SCS to be connected
The I device 4 is connected in a daisy chain manner through a SCSI bus 6. The software that runs on the information processing device 2 ′ includes a setting utility 31, an application 32, an OS kernel 33, and a SCSI host adapter device driver 34.

An instruction is passed to the host adapter 1 and the SCSI
The target SCSI device 4 connected to the host adapter 1 'is accessed. Here, software (Device) for directly accessing hardware, such as Device Driver 34 for SCSI host adapter, is used.
Driver) is prepared exclusively for each hardware. Also, software dedicated to the SCSI host adapter for setting the SCSI host adapter 1 and the like is set apart from the application 32 by using the setting utility 31.
And

Next, the detailed configuration of the SCSI host adapter 1 'will be described. In this embodiment, each SCSI
The value of the data transfer rate set for the device 4,
A storage unit for storing and storing necessary items from the specification information of each SCSI device 4 is realized by hardware in the SCSI host adapter 1. The SCSI host adapter 1 ′ includes a host bus connector 11, a host bus control unit 12, a SCSI bus control unit 13, a SCSI bus terminator 14, and SCSI host adapter control software (usually referred to as SCSI-BIOS) 15. , SC
SI bus connector 16 and setting information storage memory 7
1

The host bus control unit 12 is connected to the host local bus 5 of the information processing device 2 'and the S
The connection with the CSI host adapter 1 'is controlled, and the command / transfer data from the information processing apparatus main body is taken into the SCSI host adapter 1' at the timing of the host local bus 5. Here, the command and data passed from the host bus control unit 12 are passed to the SCSI bus control unit 13 and data is transferred to and from the SCSI device 4 connected through the SCSI bus 6 using a protocol conforming to the SCSI standard. The setting information storage memory 71 uses a readable and writable storage element such as a random access memory (RAM). This setting information storage memory 71 stores each S
In order to store the value of the data transfer rate set for the CSI device 4 and the necessary items from the specification information of each SCSI device 4, a table for each ID as shown in FIG. Items can be read out. FIG. 6 shows a configuration example of a logical storage table of information stored in the setting information storage memory 71.

Here, an example is shown in which the type of the connected device (hard disk, CD-ROM, etc.), the transfer method, and the value of the transfer speed set for the device are stored for each SCSI_ID.

Next, the operation will be described with reference to FIGS. First, the value of the data transfer speed set for each SCSI device 4 and
An operation of storing necessary items obtained from the specification information of the CSI device 4 will be described.

In the initialization processing performed at the time of starting and resetting of the information processing apparatus 2 'in FIG. 4, the initialization processing of the SCSI host adapter 1' is also performed. The initialization process of the SCSI host adapter 1 'is started when a reset signal is output on the host local bus 5 when the power is turned on to the information processing device 2' and the reset process is executed. SCSI host adapter 1 'and connected SC
The flow of initialization of the SI device 4 will be described with reference to FIG.

A reset signal input to the SCSI host adapter 1 'starts an initialization program of the SCSI host adapter control software 15 incorporated in the SCSI host adapter 1', and initializes the SCSI host adapter 1 'itself. Initialize the connected SCSI device 4. At 61, initialization of the SCSI control unit (controller unit) is started by resetting the SCSI host adapter 1 '. At 62, the SCSI bus is initialized. This stops each SCSI device 4 connected to the SCSI bus 6 from driving (using) each signal line after the power is turned on, and initializes a phase (a certain processing state during processing) of each SCSI device 4. I will return to the state. All SC
The state in which the SI device 4 does not use the bus is called bus free.

After confirming that the SCSI bus 6 is in the bus free state, the connection of each SCSI device 4 is confirmed at 63 in the order of ID. The SCSI host adapter 1 'checks its own ID (generally "7") and the target (S
ID of the CSI device 4) (here, “0” to “6”)
) And the ATN line are asserted (true: “Low”), and the BSY signal is deasserted (false: “High”) (selection phase).

When each SCSI device detects that its own ID is asserted, it responds by asserting the BSY signal. That is, the SCSI device 4 notifies the SCSI host adapter 1 that the ID (self) exists. The SCSI host adapter 1 performs this operation for all IDs.

This series of operations is performed by the SCSI command "T".
est Unit Ready command ”or the like. At 64, the SC connected to the SCSI device 4 confirmed to be connected at 63
The feature information (specification information) of the SI device 4 is extracted. This information includes a device type, a function level of a supported function, and the like. The transfer information includes support information of the transfer method, and includes information indicating whether synchronous transfer is supported. At 65, the setting parameters of each SCSI device 4 are set in the SCSI bus control unit 13. The set value of the data transfer speed is based on the information
The transfer negotiation is performed on (the ID of the SCSI device 4 whose connection has been confirmed), and the data transfer speed for the SCSI device 4 is determined. This set value will be used at the time of data transfer performed between the SCSI host adapter 1 and the SCSI device 4 in the future.

Here, the feature information acquisition operation is realized by the SCSI command "Inquire command" or the like. At 66, the setting information storage memory 71 stores the SCS at 65.
The same transfer speed as the value set in the I control unit and the data required in the feature information as additional information are written. The information to be written is the type of the SCSI device 4, the transfer method, and the set transfer speed, and an example of a table to be stored is shown in the table. Here, as the SCSI device 4 type, the device type is identified from the value obtained from the device type code in bits 4-0 of the 0th byte in FIG. In the transfer method, if the bit 4 “SYNC” bit of the seventh byte is “1”, synchronous transfer is performed, and if “0”, asynchronous transfer is performed. A series of flows from 63 to 66 are sequentially performed for all IDs whose connection has been confirmed. In 67, other SC
Various settings relating to the SI bus control unit 13 are performed, and the initialization is completed.

Next, the operation of extracting the stored data by the operator will be described. The operator obtains information by operating the setting utility on the information processing device. As an operation flow, a command to display the information in the information setting storage memory 71 by operating the setting utility 31 is issued. Setting utility 31 operated by the operator
When the setting information storage memory 71 on the SCSI host adapter 1 'is accessed, the following control is performed.

A read command from the setting utility 31 to the setting information storage memory 71 is sent to an Operating System kernel 3 such as a Windows system.
3 through Device D for SCSI host adapter
The command is converted into a command for directly accessing the hardware by the river 34 and the command is passed to the SCSI host adapter 1 ′. Upon receiving this instruction, the host bus control unit 12 accesses the setting information storage memory 71, reads out the stored data, and reads the device for the SCSI host adapter.
Operating Sy through Driver34
Delivered to the stem kernel 33. By displaying this data on the display unit of the information processing device 2 ', the operator can confirm the current setting status. FIG. 8 shows an example of a case where the information is displayed on the display unit of the information processing apparatus.

Next, another system configuration using the SCSI host adapter according to the present invention will be described with reference to FIG. The information processing apparatus 2 ″ includes a SCSI host adapter 1, software 3, and a host local bus 5.
This information processing device 2 ″ has an external device for storing information,
An external storage device 8 is provided. The external storage device 8 is connected to the host local bus 5 and stores information such as a data transfer speed set between the SCSI host adapter 1 and the SCSI device 4 as a digital data file.

The configuration and operation of the preferred embodiment of the SCSI host adapter according to the present invention have been described above. However, the present invention should not be limited to only such specific examples, and those skilled in the art can easily understand that various modifications can be made without departing from the gist of the present invention.

[0061]

The first effect is that after the system of the information processing apparatus (including the connected SCSI device) is activated, the SC
The operator can confirm the data transfer speed set between each SCSI device connected to the SI host adapter. The reason is that information set only in the SCSI control unit is also stored in a storage unit accessible from the outside. Further, the contents can be read out and displayed by software.

The second effect is that the transfer Negotiation
In the case of n, a SCSI device responding with an erroneous value is operated at an erroneous transfer speed, thereby preventing problems such as data destruction. The reason is that the operator sets the transfer rate (Ultra-SCSI on the SCSI bus) in addition to the cable length and the number of connected devices.
This is because it can be visually confirmed whether or not it is in the environment.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an entire system using a SCSI host adapter according to the present invention.

FIG. 2 is a configuration diagram of a preferred (first) embodiment of the SCSI host adapter in FIG. 1;

FIG. 3 is a diagram showing a configuration example of a logical storage table of information stored in a setting information storage unit 7 in FIG.

FIG. 4 is an overall configuration diagram of another system using the SCSI host adapter according to the present invention.

FIG. 5 is a configuration diagram of another (second) embodiment of the SCSI host adapter in FIG. 4;

6 is a diagram showing a configuration of a logical storage table of information stored in a setting information storage memory 71 in FIG.

FIG. 7 is a flowchart illustrating an initialization processing operation of the SCSI host adapter according to the present invention.

FIG. 8 is an example of a display screen of the setting utility of FIG. 4;

FIG. 9 is a configuration diagram of still another system using the SCSI host adapter according to the present invention.

FIG. 10 is a configuration diagram of a general SCSI system.

FIG. 11 is an initialization flowchart of a conventional SCSI host adapter.

FIG. 12 is a flowchart of a method for setting a transfer speed of the SCSI host adapter of FIG. 11;

13 is a diagram showing an example of the content of the feature information in FIG.

[Explanation of symbols]

 1, 1 'SCSI host adapter 2, 2', 2 "information processing device 4 SCSI device 5 host local bus 6 SCSI bus 7, 8 storage unit 11 host bus connector 12 host bus control unit 13 SCSI bus control unit 14 SCSI bus Terminator 16 SCSI bus connector

Claims (6)

[Claims] 1. A plurality of SCSI devices connected to a SCSI bus.
In a system including a device and an information processing device,
A SCSI host adapter that performs processing for setting a data transfer rate with each of the SCSI devices; a host bus control unit that receives a command and transfer data from the information processing device via a host local bus in the information processing device; A SCSI bus control unit for transferring data from the host bus control unit to the SCSI device via the SCSI bus according to a SCSI protocol. 2. A host bus connection connector for connecting the host bus control unit and the host local bus,
CSI bus control unit and SC for connecting the SCSI bus
The SCSI host adapter according to claim 1, further comprising an SI bus connection connector. 3. The SCSI host adapter and the SCS
The SCSI host adapter according to claim 1, further comprising an externally accessible storage unit that stores a data transfer rate determined between the I devices. 4. The SCSI according to claim 3, wherein said storage unit is provided in said information processing apparatus.
Host adapter. 5. A display device according to claim 3, further comprising a display device for reading the individual information data of the plurality of SCSI devices and the value of the data transfer speed written in the storage unit and displaying the data as a table. The SCSI host adapter as described. 6. The SCSI bus control unit includes the SCS
2. The SCSI host adapter according to claim 1, further comprising a SCSI bus terminator for shaping the waveform of the SCSI bus according to a connection mode of an I device.