(19) Japan Patent Office (JP)
`(12) Official Gazette of Unexamined Patent Applications (A)
`
`
`
`Identification Code
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`
`
`Internal File Nos.
`
`
`(11) Patent Application Publication Number: H4-15853
`(43) Patent Application Publication Date:
`January 21, 1992
`
`
`
`(51) Int. Cl.5
`
` G
`
` 06 F 13/36
`
`
`Request for Examination: Received
`Number of Claims: 1
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`(54) Title of the Invention: SCSI Device Converter
`
`(21) Application Number:
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`(22) Application Date:
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`(72) Inventor:
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`
`
`320 A
`
`
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`H2-120493
`
`May 9, 1990
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`7052-5B
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`(Total of 6 Pages)
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`
`Noboru KAWAGUCHI
`Sanyo Machine Works, Ltd.
`1, Azaoka, Oazaoki-mura, Nishiharu-cho,
`Nishikasugai-gun, Aichi-ken
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`
`Mitsutoshi GOTO
`Sanyo Machine Works, Ltd.
`1, Azaoka, Oazaoki-mura, Nishiharu-cho,
`Nishikasugai-gun, Aichi-ken
`
`Sanyo Machine Works, Ltd.
`1, Azaoka, Oazaoki-mura, Nishiharu-cho,
`Nishikasugai-gun, Aichi-ken
`
`Shogo EHARA, Patent Attorney
`
`
`
`1
`
`
`(72) Inventor:
`
`
`(71) Applicant:
`
`(74) Agent:
`
`
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`
`
`Apple 1005
`U.S. Pat. 6,470,399
`
`

`
`Specification
`
`
`
`
`
`1. Title of the Invention
`
`SCSI Device Converter
`
`2. Claims
`
`(1) A SCSI device converter comprising: a SCSI interface connected to a
`SCSI interface in an engineering workstation (EWS) for connecting a hard
`disk;
`a device interface for connecting a peripheral device;
`a data writing unit, data reading unit, control data writing unit, and an
`interrupt data reading unit each identified by the EWS through the SCSI
`interface by a different ID number (or by the same ID number but a
`different unit number);
`a code converting unit interposed between the data writing unit, the reading
`unit, and the device interface for converting data between the SCSI format
`and the peripheral device bus format;
`a control unit for controlling the transmission/reception of data between the
`EWS and the peripheral device through the data writing unit and reading
`unit are interrupted; and
`an interrupt control unit for outputting a disconnect signal via the SCSI
`interface to the EWS to release an EWS line when the data reading unit has
`not prepared interrupt data for an interrupt data read command sent from
`the EWS, and afterwards for sending a reconnect signal to the EWS via the
`SCSI interface to enable the EWS to read interrupt data when interrupt data
`has been inputted from a device to the interrupt data reading unit.
`
`
`
`3. Detailed Description of the Invention
`
`(Field of Industrial Applicability)
`
`The present invention relates to a general SCSI device converter which is
`able to easily connect a device such as a PC peripheral device or a sequencer
`to a SCSI interface on an engineering workstation (EWS).
`
`(Prior Art and Problem Solved by the Invention)
`
`
`2
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`

`
`Engineering workstations (EWS) include a collection of inexpensive devices
`which facilitate high-speed processing via multi-tasking and multi-window
`processing.
`
`An EWS includes, as a standard interface, a SCSI interface used to connect
`hard disks and magnetic disk drives. However, they do not include
`expansion slots such as personal computers. As a result, output devices such
`as plotters and sequencers which have a personal computer I/O bus or bi-
`directional parallel bus with interrupt for a personal computer cannot be
`connected directly to an EWS. In other words, because current EWS only
`have an initiator function, a circuit connection cannot be established from a
`converter to an EWS.
`
`While a personal computer can be connected to a wider variety of peripheral
`devices by using the expansion slot, it has a slower processing speed and
`not practical because of single-task processing. An higher grade EWS has a
`dedicated bus for connecting peripheral devices, but it is for specific device,
`so it cannot be connected to any peripheral device and the system
`configuration is very expensive.
`
`When an EWS is connected to a peripheral device with a PC-compatible bus,
`the process requires a standard SCSI interface designed to accommodate a
`hard disk, a PC-compatible GPIB interface, and a code converter connected
`to these interfaces to perform the necessary code conversion.
`
`However, current SCSI interfaces designed for hard disks do not have an
`interrupt function, and the device which is required to interrupt on the host
`end such as by a sequencer cannot be connected.
`
`Therefore, it is an object of the present invention to provide a general SCSI
`device converter which enables a peripheral device having a bus standard
`differ from SCSI such as PC bus to be easily connected to the SCSI interface
`on a EWS designed to connect a hard disk, and especially allows the
`peripheral device end to interrupt.
`
`(Means of Solving the Problem)
`
`The present invention is a SCSI device converter comprising: a SCSI
`interface connected to a SCSI interface in an engineering workstation (EWS)
`for connecting a hard disk; a device interface for connecting a peripheral
`device; a data writing unit, data reading unit, control data writing unit, and
`an interrupt data reading unit each identified by the EWS via the SCSI
`interface by a different ID number (or by the same ID number but a
`different unit number); a code converting unit interposed between the data
`
`3
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`

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`writing unit, the reading unit, and the device interface for converting data
`between the SCSI format and the peripheral device bus format; a control
`unit for managing the transmitting/receiving of data between the EWS and
`the peripheral device via the data writing unit and reading unit are
`interrupted; and an interrupt control unit for outputting a disconnect signal
`(conforming to SCSI standards) via the SCSI interface to the EWS to release
`an EWS line when the data reading unit has not prepared interrupt data for
`an interrupt data read command sent from the EWS, and afterwards for
`sending a reconnect signal (conforming to the SCSI standards) to the EWS
`via the SCSI interface to enable the EWS to read interrupt data when
`interrupt data has been inputted from a device to the interrupt data reading
`unit.
`
`(Operation)
`
`The above-described SCSI device converter is able to input and output data
`to a SCSI interface of an EWS using the same standards as SCSI interface
`for a hard disk, and enables the above-described four units, i.e., the data
`writing units and data reading units, which allow the EWS to operate as a
`data relay point with a peripheral device, to write and read data.
`
`This SCSI device converter also inputs data to and outputs data from a
`peripheral device via a device interface by using a device bus standard, and
`the data is converted into SCSI standard data by a code converting unit, and
`is inputted to and outputted from the above-described four units, i.e., the
`data writing units and data reading units.
`
`To an interrupt data read command from the EWS, the interrupt control unit
`temporarily releases the line to the EWS using a disconnect signal and
`reconnect signal of SCSI standards when data is not prepared in the
`interrupt data reading unit, and data reading is performed when the data is
`prepared thereafter.
`
`This operation enables the SCSI interface of the EWS, which is not equipped
`to handle an interrupt from a device, to perform a virtual-interrupt
`operation, and enables the SCSI interface of the EWS, which is designed for
`connecting a hard disk, to connect a device requiring an interrupt.
`
`(Embodiment)
`
`The following is an explanation of a configuration shown in FIG. 1 in which a
`peripheral device is connected to an EWS using a SCSI device converter in
`an embodiment of the present invention.
`
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`4
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`

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`In this drawing, (1) indicates a relatively inexpensive EWS (Engineering
`Workstation) such as a desk top typewhich has a SCSI interface (2) as
`standard equipment for connecting with the hard disk. (3) indicates a SCSI
`device converter installed in one boardwhich connects the EWS (1) to a
`peripheral device, for example, an output device (4) such as a plotter, an
`input device (5) such as a CD-ROM, and a device (6) that performs interrupt
`control such as a sequencer.
`
`The SCSI device converter (3) includes a SCSI interface (7) for connecting
`to the EWS (1), and includes personal computer I/O bus interfaces (8) (9)
`and an interface for a bi-directional parallel bus interface (10) with interrupt
`function as interface for connecting peripheral devices. The SCSI device
`converter (3) also implements a data writing unit (11), a data reading unit
`(12), a control data writing unit (13), an interrupt data reading unit (14), a
`code converting unit (15), a control unit (16) and an interrupt control unit
`(17) by using a microcomputer, ROM and RAM. The data writing unit (11),
`the data reading unit (12), the control data writing unit (13) and the
`interrupt data reading unit (14) are identified in different ID numbers N,
`N+1, …, and N+3 (or by the same ID number but different unit numbers N,
`N+1, …, and N+3) by the EWS (1) through the SCSI interface (2) (7).
`The codeconverting unit (15) and the control unit (16) are located between
`each of the data writing units and reading units (11) (12) (13) (14) and the
`device interfaces (8) (9) (10). The code converting unit (15) converts the
`data format between SCSI standards and device-interface bus standards.
`The control unit (16) controls the data transmission/reception between the
`EWS and the peripheral devices which is performed by relaying the data
`writing units and reading units. The interrupt control unit (17) generates a
`control signal so that the EWS (1) can receive interrupt signals from the
`devices through the SCSI interfaces (2) and (7) without terminating
`processing.
`
`In addition to the I/O interfaces (8) (9) and interface for a bi-directional
`parallel bus with interrupt (10) mentioned above, the SCSI device converter
`(3) can be adapted to accommodate any other type of device interface. For
`example, an A/D converter (19) may be installed to receive analog data
`from an analog device (18) such as a sensor. The device interface used here
`can be a standard interface such as a RS-232, Centronics, or VME bus, or a
`special interface such as the expansion buses used in each personal
`computer.
`
`The following is an explanation of the operations performed by an EWS
`device converter (3) with this configuration.
`
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`5
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`The SCSI interface in the EWS (1) is designed to connect up to eight hard
`disks. In the present invention, the various writing units and reading units
`(11) … (14) are assigned ID numbers (or the same ID number but different
`unit numbers) (N, N+1, …, N+3) so that the EWS (1) can identify, in
`appearance, the data writing unit (11), the data reading unit (12), the
`control data writing unit (13), and the interrupt data reading unit (14) as
`four hard disk devices . In other words, the EWS (1) writes or reads data to
`each writing unit or from each reading unit using the same method as that
`for four hard disks.
`
`The control unit (16) controls the input and output of data to the peripheral
`devices (4) (5) (6) via the device interfaces (8) (9) (10). In other words,
`data written to the data writing unit (11) is outputted to an output device
`(4) such as a plotter, data read from an input device (5) such as a CD-ROM
`is inputted to the data reading unit (12), data written to the control data
`writing unit (13) is outputted to a device (6) performing interrupt control
`such as a sequencer, and interrupt data from the device (6) performing
`interrupt control is inputted to the interrupt data reading unit (14). The
`input/output control by the interrupt control unit (17) is performed on a
`predetermined timing by interpreting commands sent from the EWS (1). The
`code converting unit (15) is involved in data transmission/reception between
`the device interfaces (8) (9) (10) and the data writing units and reading
`units (11) (12) (13) (14) to convert code between the SCSI standards and
`each bus standard. The device interfaces (8) (9) (10) can be controlled by
`the code converting unit (15), the control unit (16) and the interrupt control
`unit (17) even when a plurality of channels exist.
`
`In the present invention, the EWS (1) recognizes the writing units and
`reading units (11) (12) (13) (14) as separate devices. As a result, the EWS
`(1) can simultaneously launch separate a writing program and a reading
`program for these writing units and reading units (11) (12) (13) (14) and
`perform parallel processing for higher processing efficiency.
`
` major feature of the present invention is to cause the SCSI interface (2) of
`the EWS (1), which is not equipped to handle an interrupt from a device, to
`perform a virtual interruption. In other words, if interrupt data is not
`prepared when a read command is issued from the EWS (1) to the interrupt
`data reading unit (14) (since an interrupt is occurred at unspecified timing in
`accordance with a state of the device, interrupt data is not prepared in many
`cases, unlike a case in which the input device (5) such as CD-ROM prepares
`data in response to the read command from the EWS (1)), the interrupt
`control unit (17) sends a disconnect signal to the EWS (1), and temporarily
`disconnects the line to the EWS. Thus, the EWS (1) can perform another
`process. Thereafter, when interrupt data is prepared in the interrupt data
`
` A
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`6
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`reading unit (14), the interrupt control unit (17) sends a reconnect signal to
`the EWS (1). The EWS (1), which has been received the reconnect signal,
`reads the interrupt data, and then the reading of interrupt data by the EWS
`(1) ends.
`
`The following is an explanation of the operations performed by a SCSI driver
`(software) of the EWS (1) performing the above-described operation.
`
`The SCSI driver of the EWS has been developed as a driver for connecting a
`hard disk. Therefore, the apparatus in the present invention operates in a
`manner emulating the hard disk. This processing procedure is performed
`according to a flowchart shown in FIG. 2.
`In this flowchart, steps from ‘Start’ to ‘Mode Sense’ represent an
`initialization process for a hard disk, ‘Inquiry’ represents reporting of
`attribute information of a target and logical units (identification code of a
`device type), ‘Start/Stop Unit’ represents start/stop of the logical unit, ‘Test
`Unit Ready’ represents testing whether or not the logical unit is available,
`and ‘Mode Sense’ represents reporting of various parameter values (data
`format, storage medium configuration). In this way, the writing units and
`reading units (11) (12) (13) (14) can be activated for the EWS (1).
`
`After the initialization process, the EWS (1) performs writing to or reading
`from the writing units and reading units (11) (12) (13) (14). In other words,
`‘Read Extended’ represents reading data from a designated block, i.e., the
`data reading unit (12) or the interrupt data reading unit (14), and ‘Write
`Extended’ represents writing data to a designated block, i.e., the data
`writing unit (11) or the control data writing unit (13).
`
`Since the above-described procedure uses a procedure as provided in the
`SCSI standards, the apparatus of the present invention can be easily
`connected to the SCSI interface of the EWS (1) without almost any
`modification.
`
`
`
` A
`
` procedure for controlling, in accordance with such standard procedure, a
`device having various interfaces compatible with personal computers will be
`explained. Controls of various devices can be separated into reading of data
`from and writing of data to a memory, writing of a command, and reading of
`an interrupt signal from a device. In the apparatus of the present invention,
`because functions are assigned to four units, i.e., the writing units and
`reading units (11) (12) (13) (14), the EWS simultaneously launches both
`reading and writing programs. Among these functions, the reading of
`interrupt data is performed according to a flowchart shown in FIG. 3, and to
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`7
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`thereby cause the SCSI interface which is not equipped to handle an
`interrupt, to perform a virtual interrupt.
`
`First, a read command is output from the EWS to the interrupt data reading
`unit (14). This reading operation needs to be periodically performed by
`anticipating intervals of occurrence of device interrupts. Since interrupt data
`is not usually prepared, the interrupt control unit (17) sends a disconnect
`signal to the EWS (1) so that the EWS (1) can release the line to the EWS
`(1) and perform another operation. Next, when an interrupt occurs at the
`device and interrupt data is prepared, the interrupt control unit (17) outputs
`a reconnect signal to the EWS (1) to cause the EWS (1) to read the interrupt
`data from the interrupt data reading unit (14). When the interrupt data has
`been sent to the EWS (1), execution of the read command ends at the EWS
`(1).
`
`(Effect of the Invention)
`
`According to the present invention, a device having an interface requiring an
`interrupt can be easily connected to the SCSI interface of the EWS which is
`not equipped to handle an interrupt.
`
`Furthermore, in the present invention, since four units, i.e., writing units and
`reading units that are identified as different logical devices are provided to
`enable reading and writing of data from the EWS to a device, enable writing
`of a command, and enable reading of interrupt data, the EWS can
`simultaneously launch writing and reading programs and perform high-speed
`processing.
`
`
`
`4. Brief Explanation of the Drawings
`
`FIG. 1 is a block diagram of a SCSI device converter in an embodiment of
`the present invention in which the SCSI device converter is connected
`between an EWS and devices, FIG. 2 is a flowchart showing a processing
`procedure of the EWS in the connection shown in FIG. 1, and FIG. 3 is a
`flowchart showing an interrupt data reading procedure in the configuration
`shown in FIG. 1.
`
`(1) ... EWS
`(2) (7) ... SCSI interface
`(3) ... SCSI device converter
`(4) (5) (6) ... Peripheral device
`(8) (9) (10) … Device interface
`(11) … Data reading unit
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`8
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`(12) … Data writing unit
`(13) … Control data writing unit
`(14) … Interrupt data reading unit
`(15) … Code converting unit
`(16) … Control unit
`(17) … Interrupt control unit
`
`
`
`Applicant Sanyo Machine Works, Ltd.
`Agents
`Shogo EHARA
`
`
`
`9
`
`
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`

`
`FIG. 1
`FIG.
`1
`
`
`Device interface
`
`
`(plotter)
`
`Output device
`
`
`
`Control
`
`data writing
`
`unit _
`Input
`device
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`
`
`
`SCSI hterface
`
`Intenupt
`data reading
`unit
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`(CD—ROM)
`
`
`
`
` Interrupt
`control device
`
`(sequencer)
`
`
`SCSI device converter
`'
`" 8
`
`
`
`
`
`
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`10
`10
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`

`
`FIG. 2
`FIG. 2
`
`
`Start/égop Unfit
`
`Read E1: tended
`or
`
`Write E-gt!-‘IIJBCIF
`
`FIG. 3
`FIG. 3
`
`
`
`Read command from EH5
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`
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`Disconnect signal from
`inI:errupl: cnntml urit to EWS
`
`Interrupt D-CCIJIS in device
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`
`
`
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`Reacing ofintemlpt data
`
`Read command ends at
`EWS
`
`
`
`11
`11
`
`Recnmect 5I'g1al from
`intenupt central unit to
`EW5
`
`

`
`Certificate of Accuracy
`
`August 3, 2016
`
`I, Frank McGee, Translator at Performance Language Solutions, hereby certify that I translated
`the attached document from Japanese into English and that, to the best of my knowledge, it is a
`true and accurate translation.
`
`I further certify that I am fluent in Japanese and English, and qualified to translate this
`document.
`
`The document is designated as:
` Japanese Patent Application Number 4-15853
`
`I declare that all statements made herein on my own knowledge are true and that all
`statements made on information and belief are believed to be true, and further, that these
`statements were made with the knowledge that willful false statements and the like so made
`are punishable by fine or imprisonment, or both, under Section 1001 of Title 18 of the United
`States Code.
`
`________________________
`Signature of Frank McGee
`
`147 West 35th Street #803
`
`New York, NY 10001
`
`
`646-736-0342
`
`Your Results, Our Priority
`
` www.performancelang.com