JP2576523B2 - External storage device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A. Industrial application fields B. Summary of the invention C. Conventional technology D. Problems to be solved by the invention E. Means to solve the problems F. Function G. Example (G-1) Implementation Example Configuration (FIGS. 1 and 2) (G-2) Operation of Embodiment (FIG. 3) H. Effects of the Invention A. Industrial Application Field The present invention relates to an external storage device in various data processing devices. In particular, there are provided recording / reproducing means for recording / reproducing data to / from a disc, and microprogram control means for interpreting a simple command given from a host computer and performing a series of writing / reading control on the recording / reproducing means. And an external storage device comprising:

B. Summary of the Invention The present invention performs a series of write / read control on the recording / reproducing means by interpreting a simple command given from a host computer by recording / reproducing means for recording / reproducing data on / from a disc. In a floppy disk drive comprising microprogram control means,
By individually resetting the recording / reproducing means and the microprogram control means based on reset data from the host computer,
The reset operation can be performed efficiently and promptly, the control dependence rate on the host computer is reduced, and the processing efficiency of the host computer is improved.

C. Prior Art Conventionally, in various data processing devices such as a personal computer and a word processor, a floppy disk device is used as an external storage device.

In general, a floppy disk device includes data processing means for writing / reading / erasing data to / from a floppy disk, rotation driving means for the floppy disk, and means for feeding various magnetic heads.

The data write operation in the floppy disk device is as follows: (1) Transfer data of one sector to the floppy disk device.

(2) Generate parity for error correction.

(3) Rotate the floppy disk.

(4) Move the head to a specified track / sector position.

(5) Data and parity are subjected to predetermined modulation processing and supplied to the head as recording data.

(6) Stop the rotation of the floppy disk.

This is performed by sequentially operating the data processing means, the rotation driving means, and the like according to the procedures (1) to (6).

The data read operation in the floppy disk device is as follows: (1) The floppy disk is rotated.

(2) Move the head to a specified track / sector position.

(3) Reproduce the data and take it into the buffer memory.

(4) Perform error correction.

(5) Transfer data for one sector to the host computer.

(6) Stop the rotation of the floppy disk.

This is performed by sequentially operating the data processing means, the rotation driving means, and the like according to the procedures (1) to (6).

Conventionally, data writing and reading operations in the floppy disk device are performed by a host computer supplying a series of control commands to the floppy disk device to sequentially execute various functional blocks such as the data processing means and the rotation driving means. And after confirming that the predetermined process has been completed, the process proceeds to the next control operation.

D. Problems to be Solved by the Invention By the way, in the conventional floppy disk drive, as described above, various functional blocks such as various data processing means and rotation drive means are sequentially performed by a series of control data supplied from the host computer. When the host computer performs the data write operation and the read operation by confirming that the predetermined process has been completed and proceeding to the next control operation, the host computer terminates the data recording and reproduction from the start to the end. Until the above, the operation control of the floppy disk drive must be performed. Therefore, the above floppy
The disk device has a problem in that the control operation occupies the processing capability of the host computer, and the processing efficiency of the host computer is significantly reduced. By interpreting a simple command given from the host computer to such a conventional floppy disk drive,
A control means for performing a series of writing / reading control on the recording / reproducing means is built-in, and externally controlled by a simple program to record / reproduce data on / from a floppy disk. Data can be efficiently recorded / reproduced without lowering the processing efficiency of the host computer.

Here, in the floppy disk device, when the control means of the recording / reproducing means for recording / reproducing data to / from the floppy disk is reset, all operations are stopped and the head is provided separately from the normal access position. After moving to the retreat area, the recording / reproducing means also stops.

Since the control means of the recording / reproducing means is reset so as to stop all the operations, the recording / reproducing means and the recording / reproducing means perform at a certain time while the processing corresponding to the reset is being executed. Since communication between the means becomes impossible, the host computer cannot give instructions to the control means during that time. Further, when the recording / reproducing means is to be operated again, it takes a long time since the spindle motor must be started to rotate the floppy disk and the head must be returned from the retreat area to the position for normal access. Therefore, in such a system, the reset cannot be performed to initialize only the recording / reproducing means during execution of the processing that can be independently performed by the control means such as the error correction processing. If any inconvenience occurs in the control means such as a malfunction of the error correction processing, the control means cannot be reset alone, and the recording / reproducing means is also reset. It takes time.

In view of the above-mentioned problems, the present invention enables external control with a simple program, and also allows the recording / reproducing means and its control means to be individually reset, thereby reducing the control dependence on the host computer. The present invention provides an external storage device having a novel configuration capable of improving the data recording / reproduction efficiency without lowering the processing efficiency of the host computer.

E. Means for Solving the Problems In order to solve the above-mentioned problems, the present invention interprets a recording / reproducing means for recording / reproducing data on / from a disc and interprets a simple command given from a host computer. Then, in an external storage device provided with a microprogram control means for performing a series of writing / reading control on the recording / reproducing means, reset data supplied from the host computer is corresponded to the recording / reproducing means, the program control means, etc. A reset register for individually holding, a reset signal generating circuit for generating a reset signal in response to an instruction from the host computer, and a gate for selectively outputting the reset signal in accordance with reset data held in the reset register And a circuit.

F. Action In the external storage device according to the present invention, based on the reset data supplied to the register from the host computer,
The recording / reproducing means for recording / reproducing data to / from the disc and the microprogram control means for performing a series of writing / reading control on the recording / reproducing means are individually reset.

G. Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

(G-1) Configuration of Embodiment In the embodiment shown in the block diagram of FIG. 1, the floppy disk device 10 according to the present invention includes an interface circuit 11 to which the host computer 1 is externally connected.
A microprogram controller 12 and a buffer memory 13 are connected to the interface circuit 11.

The microprogram control unit 12 interprets a simple command supplied from the host computer 1 via the interface circuit 11 and supplies a microcode for performing a series of write / read control to the command execution unit 14. .

Here, as the buffer memory 13, for example, a static RAM having a storage capacity of about 8 Kbytes is used. The buffer memory 13 is connected to an error correction processing unit 15 and a recording / reproducing / erasing circuit 18 via a data demodulation circuit 17 of a data modulation circuit 16.

Then, the instruction execution unit 14 performs the data modulation circuit 16, the data demodulation circuit 17 and the recording / reproduction / reproduction in accordance with the microcode supplied from the microprogram control unit 12.
The operation of the erasing circuit 18 and the like is controlled and the magnetic head 20 is controlled.
The control data is supplied to a mechanical deck system controller 19 which performs drive control of a head feed motor 22 for moving the disk on the radius of the floppy disk 21 and a spindle motor 23 for rotating the floppy disk 21.

In this embodiment, the interface circuit 11
Has five types of registers for interfacing with the host computer 1, a 1-byte reset register, a 1-byte status register, a 1-byte command register, a 4-byte parameter register, and a 1-byte data register. .

The five _{registers, A 0, A 1, RD} , WR, CS, the DACK 6
According to the bit data, selection is made as shown in Table 1.

The reset register stores the floppy
Reset data for performing initialization of the disk device 10 and calibration of the drive is provided. When the reset data is given to the reset register,
In the floppy disk device 10, the spindle motor 23 immediately stops, and the magnetic head 20 returns to the home position.

Here, as shown in FIG. 2, the main part of the interface circuit 11 is the host computer 1.
8 bits of reset data (D ₇ , D ₆ , D ₅ , D ₄ , D ₃ , D ₂ , D ₁ , D ₀ ) supplied from the host computer 1 via the data bus Reset register
A reset pulse creating circuit 31 that creates a reset pulse based on the write pulse and a reset pulse created by the reset pulse creating circuit 31 are given to the reset register 30. Reset data (D ₇ , D ₆ , D ₅ , D ₄ , D ₃ , D ₂ , D ₁ ,
D ₀ ) and a plurality of gates 32,3 for selectively outputting according to
Has three. In this embodiment, the 8 of the bits of the reset data _{(D 7, D 6, D} 5, D 4, D 3, D 2, D 1, D 0), the least significant bit D ₀ the microprogram control used as a reset flag parts 12, also the lower second bit D ₁ is used as a reset flag for the mechanical deck-system controller 19, applying a reset individually to the microprogram controller 12 and the mechanical deck system controller 19 Is available.

Also, the status register is
Indicates each state of the disk device 10 by 8 bits, the most significant D ₇ bit _{D 7 (Non-DMA Data Request} ) flag handshake in the case of performing data transfer between the external system or host computer 1 Used for purposes. The D ₇ (Non-DMA Data Request) flag becomes “1” every time data transfer becomes possible, becomes “0” during data transfer, and becomes “1” again when 1-byte data transfer is completed. , And the reversal is repeated up to the determined number of transfers. The following D ₆ bits D ₆ (No Media) flag indicates the mounted state of the floppy disk 21, when the floppy disk 21 is not loaded, or floppy disk by the eject button operation during wear It becomes "1" when 21 is pulled out. D ₅ of the next D ₅ bits (Media Change) flag, floppy disk
21 indicates that the floppy disk may have been replaced, either at reset or after the floppy disk has been ejected.
When the floppy disk 21 is not mounted, or when the floppy disk 21 is pulled out by operating the eject button during mounting, the value is set to "1". In addition, the D ₅ (Media Chan
ge) The flag returns to "0" when the data is correctly read from the floppy disk 21. The next D ₄ bit D ₄ (Write Protect) flag indicates that writing to the floppy disk 21 is prohibited.
It becomes "1" when the floppy disk 21 for which writing is prohibited is mounted and when the floppy disk 21 is not mounted, and becomes "0" when the writable floppy disk 21 is mounted. Next D ₃ bits and D ₂ bits of _{D 3 (ECC Error (MSB)} ) flag and D
_{2 The} (ECC Error (LSB)) flag indicates, in two bits, what kind of error has occurred in the process of error detection and correction automatically performed by the error correction processing unit 15 in the read processing. Are shown as two status values.
The following D ₁ bits D ₁ (Drive Error) flag indicates a malfunction of the drive, "1", then the read / write / erase run successfully if the functions of the drive was not successful Until the reset command is received, or until the reset command is received, the state of “1” is held. The D ₀ (Command Busy) flag of the least significant 0 bit indicates an execution state of a command other than the reset command, and becomes “1” during execution and processing of a command other than the reset command. Is returned to "0" with the end of.

The command register contains the floppy
All command data for controlling the disk device 10 are given, and are designated by setting bits corresponding to respective basic functions to "1". The microprogram control unit 12 interprets the contents of the 1-byte command data given to the command register by the host computer 1, and instructs the instruction execution unit 14 to erase, record, or reproduce data. Are automatically executed in a predetermined sequence.

D the uppermost side of the command register ₇ bit and D ₆
The drive specification command (Unit Select1, Uni
t Select2) is given. Up to four drives can be specified by the 2-bit drive specification command (Unit Select1, Unit Select2). Next D ₅
Execution inhibit command (Execution Inhibit)
Is given. By this D ₅ bits to "0", disabling the functions specified in the lower D ₄ to D ₀ bits. When performing the process with execution, the D ₅ bits to "1". Also, the D ₄ bits, commands the rotation of the spindle motor 23 (Mon: Motor On) command is applied. The spindle motor 23 is rotated by the D ₄ bits to "1". Further, the spindle motor 23 by the D ₄ bits to "0", and stopped after a predetermined time. Further, the magnetic head 20 moves from the home position to the outermost peripheral side when the spindle motor 23 starts rotating, and returns from the current position to the home position when the spindle motor 23 stops. Incidentally, it is not necessary to set to "1" every time the D ₄ bits are usually read / write / erase operation, the microprogram control unit 12, also the D ₄ bits is "0", The rotation of the spindle motor 23 is automatically started with the read / write / erase processing, and is stopped after a lapse of a predetermined time from the end of the processing. The following D ₃ bits, transfer of data (Data Transfer) command is supplied. By this D ₃ bits to "1", transmitting and receiving data between the floppy disk device 10 and the host computer 1. The transmission and reception of the data is performed by sequential transfer to and from the buffer memory 13 via a data register. In this case, the number of transfer data can be selected from 4K bytes, 512 bytes, and 256 bytes, and the addresses within each 4K bytes can be specified. The buffer memory 13 stores the host computer 1 regardless of the operation of the floppy disk device 10.
Can be used as temporary bank memory of 4K
512 bytes, 256 bytes as well as physical sector units of bytes
Access can also be made in byte logical sector units. The following D ₂ bits, erase (ER: Erase) command is applied. By the D ₂ bits to "1", the erase physical sector units specified by the parameter register is performed. The following D ₁ bit, write (WR: Write) command is applied. By the D ₁ bit to "1", it is written in physical sector unit specified by parameter registers. When an index is specified in the parameter register, an index signal is recorded. Here, in response to the write (WR) command, the microprogram control unit 12 performs processing according to a predetermined sequence for writing data to the floppy disk 21, and generates parity data / sub data for error correction processing. The code data / header information is automatically generated by the error correction processing unit 15 and sequentially output according to a predetermined format. Note that a series of operations of data transfer / erase / write can be executed by the write (WR) command, and the microprogram control unit 12 automatically performs processing according to a predetermined sequence. The following D ₀ bit, read (RD: Rea
d) Command is given. By setting the _D0 bit to “1”, reading is performed in physical sector units specified by the parameter register. If an index is specified in the parameter register, it becomes invalid and a drive error occurs in the status register. Here, in response to the read (RD) command, the program control unit 12 performs a process according to a predetermined sequence for reading data from the floppy disk 21 and reads a signal from the floppy disk 21. At the same time, the buffer memory
13 Error data detection /
The correction processing is performed by the error correction processing unit 15. The data transfer from the floppy disk 21 to the buffer memory 13 and the data transfer from the buffer memory 13 to the host computer 1 can be executed by the read (RD) command. 12 automatically performs processing according to a predetermined sequence. When the reading is completed normally, the reproduced track / sector number is written to the parameter register.

Further, the parameter register is provided with parameter data for designating a track / sector number when reading / writing / erasing is performed in physical sector units, erasing in track units, and writing an index signal.
This parameter register is composed of 4 bytes, and the register pointer advances each time 1 byte is read or written, and when the reading of the 4th byte or the writing of the 2nd byte is completed, the access is further continued. The pointer returns to the first byte.
The pointer returns to the first byte when a register other than the parameter register is accessed, and the order of accepting the parameter registers is initialized.

The first byte of the parameter register is read /
A physical sector address with write / erase processing;
It is used as a sector register for data transfer between the buffer memory 13 and the host computer 1 for specifying a virtual logical sector address, selecting a logical sector size, writing an index, and erasing a track. . In this sector register, three types of logical sector sizes are selectively designated by the most significant two bits (D ₇ , D ₆ ), and index writing designation and erasing of the entire track are designated [1, 1 ]. The most significant two bits (D ₇ , D ₆ ) of the sector register are set to [1,
By giving a write / erase combination command to the command register as [1], the microprogram controller 12 performs write processing of an index signal after erasing the entire track once. By writing the index signal to the floppy disk 21 in this manner, the above floppy disk 21
Can be accessed for each physical sector. The next two bits (D ₅ , D ₄ ) specify the physical sector address of 4 Kbytes. The value becomes valid when the read processing is normally performed. The collation with the physical sector address specified on the one side can be performed. The four least significant bits (D ₃ , D ₂ , D ₁ , D ₀ ) specify a logical sector address in units of 512 bytes.

The second byte of the parameter register is used as a track register for specifying a track number. In this track register, when the reading process is normally performed, the lower 7 bits become valid as a track number, and can collate with a track address specified by the host computer 1 as necessary. Further, the third byte and the fourth byte of the parameter register
In the byte, a 2-byte copy prohibition code (CPC: Copy
Protection Code).

The data register is used when data is transferred between the floppy disk device 10 and the host computer 1. The data register supports both program (PRO) transfer and DMA transfer. Also in this case, data transfer is performed via this register.

(G-2) Operation of the embodiment And the floppy disk drive 10 of this embodiment
First, as shown in the flowchart of FIG. 3, the D ₄ (Mon) bit and D ₂ (ER) of the command register are obtained by the command data given from the host computer 1 to the command register. Bit, D ₁
(WR) performs bit or D ₀ (RD) of whether "1" is set in any bit determination (step 1), if the determination result is "Y", a floppy disk 21 is mounted It is determined whether or not it has been performed (step 2). If the result of this step 2 is "Y", that is, if the floppy disk 21 is loaded, then in the next step 3, the control microcomputer (μCOM) of the mechanical deck system controller 19 is in the middle of the processing operation. It performed for determining whether or not there is, when the control microcomputer (μCOM) is released from the processing operation, D ₂ (ER) bits of the command register, D ₁ (WR) bit or D ₀ (RD) bit It is determined whether or not "1" has been set in any of the above (step 4). If the result of the determination in step 4 is "Y", that is, if any one of the erase (ER), write (WR) and read (RD) operation commands has been issued by the host computer 1,
Perform the determination of the presence or absence of drive specification (Step 5) by D _7, D ₆ bits of the command register, if the self-drive specification has not been made, disk surface number (SURF
#), Drive number (DR #), and motor-on signal (Mon)
Is given to the mechanical deck system controller (MD) 19 (step 6), and in the next step 7, it is determined whether or not the control microcomputer (μCOM) of the mechanical deck system controller 19 is in the middle of the processing operation. After the control microcomputer (μCOM) is released from the processing operation, the track number (TR #) set in the parameter register is given to the mechanical deck system controller (MD) 19 (step 8).
If the result of the determination in step 5 is "Y", that is, if the drive is designated, the process immediately proceeds to step 8 where the track number (TR #) is given to the mechanical deck system controller (MD) 19, and It is determined in step 9 whether or not the D ₀ (RD) bit of the command register is set to “1”. If the result of the determination in step 9 is "N", that is, if the read operation has not been designated, the data provided to the data register is transferred to the buffer memory 13 (step 10), and the next in step 11 is "1" to the D ₁ (WR) bits of the command register to determine whether or not has been set. D ₇ determination result is a "Y" or specify a write operation by the host computer 1 has been made, at the next step 12 the first byte i.e. sector register of the parameter register of the step 11, D ₆ By checking the bit, it is determined whether or not the index is designated to be written. If the writing of the index has not been designated, the process proceeds to step 13 where the error correction processing section 15 performs parity encoding (ENC) on the data written in the buffer memory 13, and In step 14, it is determined whether or not "1" is set in the D ₂ (ER) bit of the command register. Note that the above steps
If the result of the determination in step 12 is "Y", that is, if the writing of the index has been designated, the process immediately proceeds to step 14 to determine whether or not the erasing operation has been designated by the host computer. If the result of the determination in step 14 is "Y", that is, the erase operation is designated, the erase operation (ER) and the write operation (WR) are performed (step 15), and the erase operation (E
R) is not specified, the write operation (W
R) alone (step 16). Step 1 above
If the determination result in 1 is "N", that is, if the recording operation is not specified, only the erasing operation (ER) is performed (step 17). Then, the above steps 15 and 16
Alternatively, when the operation of step 17 is performed, the completion of the operation of step 15, step 16 or step 17 is confirmed by checking the D ₀ (Command Busy) flag of the status register in the next step 18, and then the operation proceeds to the next step 19. Then, it is determined whether or not “1” is set in D ₄ (Mon) of the command register (step 19). If the determination result in step 19 is "N", in the next step 20, it is determined whether or not the control microcomputer (μCOM) of the mechanical deck system controller 19 is in the middle of the processing operation. When the control microcomputer (μCOM) is released from the processing operation, the disk surface number (SURF #), drive number (DR #), and motor off signal (Moff) are sent to the mechanical deck / system controller (MD) 19. After being given (step 21), the apparatus enters a standby state (step 22).

If the result of the determination in step 1 is "N", that is, if the host computer 1 has not commanded the operation of the floppy disk device 10, the process proceeds to step 23, where the control microcomputer of the mechanical deck system controller 19 is controlled. (ΜCOM) determines whether or not the processing operation is in progress, and when the control microcomputer (μCOM) is released from the processing operation, the disk surface number (SURF #) and the drive number (DR #) And a motor-off signal (Moff) to the mechanical deck / system controller (MD) 19 (step 24), then perform data transfer (step 25), and enter the standby state of step 22. If the result of the determination in step 4 is "N", that is, only the rotation of the spindle motor 23 has been designated (Mon) by the host computer 1, the erasing operation (ER),
If the write operation (WR) and the read operation (RD) have not been specified, the process proceeds to step 26, where the disk surface number (SURF #), drive number (DR #), and motor-off signal (Moff) are transmitted to the mechanical deck. After being given to the system controller (MD) 19 (step 24), the above step 25
Data transfer. If the result of the determination in step 2 is "N", that is, if the floppy disk 21 is not mounted, the flow proceeds to step 27 to determine whether or not a drive has been designated. The process enters the standby state of step 22, and when another driver is designated, the process proceeds to step 20 described above.

If the result of the determination in step 9 is "Y", that is, if the read operation (RD) has been set by the host computer 1, the process proceeds to step 28, where various flags are reset, and then the floppy disk drive is reset. Read data from the disk 21 to the buffer memory 13 (step 29). When the data read operation in step 29 is performed, the end of the operation in step 27 is confirmed in the next step 30 by checking the D ₀ (Command Busy) flag in the status register. Turning to look at D ₁ bit of the status register, the magnetic head 20 is determined whether correctly sent by normal data read operation on a target track is performed in step 29, if no drive error is ,
The error correction processing section 15 performs error correction processing (DEC) (step 32). Then, in the next step 32, it is determined whether or not there is an error that cannot be corrected by the error correction processing in the above step 32, and if there is no error, the track number (SUB-CODE) included in the sub-code data (SUB-CODE) of the data read out TR #), the sector number (SC #) and the copy prohibition code (CPC) are transferred to the parameter register (step 34), and the subcode data (SUB-COD) is transferred.
The presence or absence of the error of E) is determined (step 35). If there is no error in the subcode data (SUB-CODE), the process of step 36 for transferring the data read to the buffer memory 13 to the host computer 1 via the data register is performed, Move to 19.

Steps 31, 33 and 35
If the result of the determination is “Y”, that is, if an error has occurred, the process immediately proceeds to step 19.

In the floppy disk drive 10 of this embodiment, the command data (D ₇ , D ₆ , D ₅ , D ₅₎ given to the command register of the interface circuit 11 by the host computer 1
₄ , D ₃ , D ₂ , D ₁ , D ₀ ) are interpreted by the microprogram control unit 12 to perform various series of control operations as described below.

[Control Operation Example 1 command data _{(D 7, D 6, D} 5, D 4, D 3, D 2, D 1, D 0) = (00100110) (1) a spindle motor on (2) magnetic head feed ( seek) (3) erase operation (4) write operation (5) a spindle motor oFF (6) magnetic head feed (calibrated) [control operation example 2 command data _{(D 7, D 6, D} 5, D 4, D 3 , D ₂ , D ₁ , D ₀ ) = (00111110) (1) Spindle motor on (2) Magnetic head feed (seek) (3) Data transfer (4) Erase operation (5) Write operation [Control operation example 3] command data _{(D 7, D 6, D} 5, D 4, D 3, D 2, D 1, D 0) = (00110110) (1) a spindle motor on (2) magnetic head feed (seek) (3) Clear operation (4) write operation [control operation example 4 command data _{(D 7, D 6, D} 5, D 4, D 3, D 2, D 1, D 0) = (00100001) (1) spindle motor Taon (2) magnetic head feed (seek) (3) read operation (4) the spindle motor off (5) the magnetic head feed (calibrated) [Control Operation Example 5 command data _{(D 7, D 6, D} 5, D 4 , D ₃ , D ₂ , D ₁ , D ₀ ) = (00111001) (1) Spindle motor on (2) Magnetic head feed (seek) (3) Read operation (4) Data transfer Here, command data (D ₇ , D ₆ , D ₅ , D ₄ , D ₃ , D ₂ , D ₁ ,
A series of control operations in the case where, for example, command data [0010110] is given to the command register of the interface circuit 11 by the host computer 1 as D ₀ ) will be described in detail.

The microprogram control unit 12 interprets the command data [0010110] and sends a rotation command signal (Mon) of the spin motor 23 and a track number (TR) from the command execution unit 14.
#) To the mechanical deck / system controller 19 by serial transfer. Upon receiving the rotation command signal (Mon) and the track number (TR #), the mechanical deck / system controller 19 activates the spindle motor 23 to rotate the floppy disk 21 and the feed motor 22
Track number (TR #) with the magnetic head 20 specified by
During the movement to the position, the microprogram control unit 12 notifies the completion of the preparation for data transfer, and the host computer 1 transmits the buffer memory 13 via the data register of the interface circuit 11.
Transfer data to In addition, the mechanical deck / system controller 19 notifies the instruction execution unit 14 that the rotation of the spindle motor 23 has been stabilized and the movement of the magnetic head 20 has been completed and the preparation for recording has been completed. Further, the error correction processing unit 15 generates an error correction parity for the data transferred from the host computer 1 to the buffer memory 11. Then, the microprogram control unit 12 notifies the instruction execution unit 14 that the mechanical deck / system controller 19 has completed the preparation for recording, and when the parity generation by the error correction processing unit 15 is completed, the floppy disk 21 Waits for the data to rotate to the start position of the target sector, and then operates the recording circuit and the erasing circuit to record data with the recording / reproducing head while erasing with the preceding erase head. Further, the microprogram control unit 12 sends a motor-off signal (Mof
f) is given by serial transfer to the mechanical deck / system controller 19 to stop the rotation of the spindle motor 23 and notify the host computer 1 of the completion of the data recording operation.

The host computer 1 monitors the contents of the status register and the parameter register while the microprogram control unit 12 performs various series of control operations of the floppy disk device 10 as described above. When a malfunction or the like is detected, reset data is supplied to the reset and register 30 of the interface circuit 11 as necessary, and the microprogram control unit 12
And the mechanical deck / system controller 19 can be individually reset. The floppy disk device 10 performs a countermeasure process against a malfunction due to the reset operation, and performs an initialization process of the mechanical deck system controller 19 while the microprogram control unit 12 is independently executing the process. By doing so, it is possible to efficiently record and reproduce data on the floppy disk 21.

In this embodiment, the microprogram control unit 12 and the mechanical deck system controller 19 are individually reset. However, devices to be reset by the number of bits of the reset register 30 can be divided.

H. Effects of the Invention As described above, in the external storage device according to the present invention, the recording / reproducing means for recording / reproducing data on / from the disk can be externally controlled by a simple program by the microprogram control means. Since the recording / reproducing means and the microprogram control means can be individually reset based on the reset data supplied from the computer to the register, the reset operation can be performed efficiently and quickly, and the control dependence rate on the host computer can be improved. And the recording and reproduction of data can be performed efficiently without lowering the processing efficiency of the host computer.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a floppy disk drive according to the present invention, and FIG. 2 is a block diagram showing a main configuration of an interface circuit constituting the floppy disk drive. FIG. 3 is a flowchart showing the operation of the floppy disk device. 1 Host computer 10 Floppy disk device 11 Interface circuit 12 Microprogram control unit 13 Buffer memory 14 Instruction execution unit 15 Error correction processing unit 16 Data modulation circuit 17 … Data demodulation circuit 18… Recording / reproducing / erasing circuit 19… Mecha deck system controller 20… Magnetic head 21… Floppy disk 22… Feed motor 23… Spindle motor 30… Reset register 31… Reset Pulse generation circuit 32,33 …… Gate

Claims (1)

(57) [Claims] 1. A recording / reproducing means for recording / reproducing data on / from a disk, and a microprogram control means for interpreting a simple command given from a host computer and performing a series of writing / reading control on the recording / reproducing means. An external storage device comprising: a reset register for individually holding reset data supplied from the host computer in accordance with the recording / reproducing means and the program control means; and a reset signal in response to an instruction from the host computer. An external storage device, comprising: a reset signal generation circuit to be generated; and a gate circuit that selectively outputs the reset signal according to reset data held in the reset register.