JPS63316373A - Magnetic disk driving device - Google Patents

Abstract

PURPOSE:To shorten a latency time at the time of reproducing data per track by possessing a capacity capable of storing the data per one tack of a magnetic disk by a buffer memory and storing reproducing data of either a track unit or a sector unit to perform an error correction. CONSTITUTION:A buffer memory 13 is connected with an error correction processing part 15 and also with a recording/reproducing/erasing circuit 18 via a data modulation circuit 16 and a data demodulation circuit 17. Control data are fed to a mechanical deck system controller 19 to perform drive controls on a head freed motor 22 for moving a magnetic head 20 radially on a floppy disk 21 and a spindle motor 23 for rotating the floppy disk 21 and so forth. Then, the reproducing data from the magnetic disk 21 are stored into the buffer memory 13 as per either of the track unit or the sector unit and then the error correction is carried out by the error correction part 15. By this method, the latency time at the time of reproducing the data per track can thus be shortened.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A. Field of industrial application B. Overview of the invention C. Prior art D. Problems to be solved by the invention E. Means for solving the problems (Figures 1 and 2) F. Effect G. Example G1. Floppy disk drive Apparatus (Figure 1) Operation of G2 floppy disk drive (Figure 3) Operation related to G3 buffer memory (Figure 2).

G4-Data recording format (Figures 4 to 9) G6
Formation of parity (Fig. 10) 06 Map of memory area (Fig. 11) H Effect of the invention A Industrial application field The present invention is suitable for magnetic disk drives suitable for floppy disk drives, hard disk drives, etc. Regarding.

B. Summary of the Invention The present invention provides a magnetic disk drive in which playback data from a magnetic disk, each track of which is composed of a plurality of sectors, is stored in a buffer memory, and error correction processing is performed on the data stored in the buffer memory. In the device,
The buffer memory has a capacity to store data for at least one track of the magnetic disk, and stores reproduced data from the magnetic disk either in track units or sector units in the buffer memory and performs error correction. By doing this, the data can be played back from the magnetic disk in sectors and tracks, and
This is designed to shorten the waiting time when the data is played back in units of trunks.

C. Conventional technology Conventionally, playback data from a floppy disk whose track consists of multiple sectors is stored in a buffer memory that has a storage capacity for one sector of data, and errors are detected in the data stored in the buffer memory. A floppy disk drive has been proposed that performs a correction process and transfers error-corrected data from a buffer memory to a computer.

D. Problems to be Solved by the Invention In a normal floppy disk drive, in order to reproduce data in a certain sector, the magnetic head is moved to the track to which that sector belongs, and the magnetic head first reads the index signal of that track. It was common practice to reproduce the data in that sector and then, after a waiting time corresponding to a predetermined rotation angle of the floppy disk (the time required for one revolution at most), to reproduce the data in that sector and write it into a buffer memory.

However, in the above-mentioned conventional floppy disk drive, the storage capacity of the buffer memory was only the storage capacity of one sector of data on the floppy disk, so there were the following drawbacks.

For example, if one track of a floppy disk consists of four sectors, each sector requires waiting time each time it is played back. Therefore, in order to play back one track of data, it takes four sectors worth of data. This method requires a waiting time, which has the drawback of increasing the waiting time.

In view of this, the present invention provides a magnetic disk in which playback data from a magnetic disk, each track of which is composed of a plurality of sectors, is stored in a buffer memory, and error correction processing is performed on the data stored in the buffer memory. The drive device is capable of reproducing data from a magnetic disk on a sector-by-sector or track-by-track basis, and also aims to shorten the waiting time when reproducing the data on a track-by-track basis.

E. Means for Solving Problems The present invention provides a buffer memory (13) in which reproduced data from a magnetic disk (21), each trunk of which is composed of a plurality of sectors, is stored, and A magnetic disk drive device (10) having an error correction processing unit (15) that performs error correction processing on data stored in the
), the buffer memory (13) has a capacity to store data for at least one track of the magnetic disk (21), and stores playback data from the magnetic disk (21) in either track units or sector units. Then, it is stored in the buffer memory (13) and sent to the error correction unit (13).
) to perform error correction.

F. Effect According to the present invention, data is reproduced from the magnetic disk (21) sector by sector or trunk by trunk and stored in the buffer memory (13), and the stored data is transferred to the error correction processing unit (15). Perform error correction processing.

G. Embodiment Below, an embodiment in which the present invention is applied to a floppy disk drive device for driving a 2-inch floppy disk will be described in detail.

G1 Floppy Disk Drive First, the overall configuration of the floppy disk drive will be explained with reference to FIG. Floppy disk drive (
10) is an interface circuit (11) to which the host computer (microcomputer) (1) is externally connected.
), and this interface circuit (11) has a microprogram control section (12) and a buffer memory (1
3) is connected.

The microprogram control unit (12) interprets simple instructions supplied from the host computer (1) via the interface circuit (11) and executes microcode for performing a series of write/read controls to the instruction execution unit ( 1
4).

Here, the buffer memory (13) is composed of, for example, a static RAM, and has five memory areas (13^) to (13E) as shown in FIG. The storage capacity of each memory area (13A) to (13g) is sufficient to write data reproduced from each sector of a floppy disk (one trunk consists of four sectors) and to perform error correction processing on the data. 6 or more part-time jobs,
Here, 6 is selected as the byte. Therefore, the total capacity of the buffer memory (13) is 30 bytes, but a 32 byte memory is used here.

The buffer memory (13) includes an error correction processing unit (15).
) is connected, and the data modulation circuit (16)
A recording/reproducing/erasing circuit (18) is connected to the data demodulating circuit (17).

The instruction execution unit (14) then executes the following according to the microcode supplied from the microprogram control unit (12).
It controls the operation of the data modulation circuit (16), data demodulation circuit (17), recording/reproducing/erasing circuit (18), etc., and also controls the magnetic head (20) on the floppy disk (21).
Control data is supplied to a mechanical deck system controller (19) that controls the drive of a head feed motor (22) that moves the head on the radius of the disk, a spindle motor (23) that rotates the floppy disk (21), etc.

In addition, each element circuit (11) to (17) is combined into an ADC
(Sometimes referred to as an atpaned disk controller).

The interface circuit (11) has five registers for interfacing with the photo 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. It has different types of registers.

These five types of registers are Ao, A1. R.D.

The 6-bit data of WR, CS, and DACK allows the first
It is now selected as shown in the table.

[Set register]

The reset register is given reset command data for initializing the floppy disk device (10) and calibrating the drive. When a reset command is given to the reset register, the spindle motor (23) is immediately stopped and the magnetic head (20) is returned to its home position.

[Status register]

Furthermore, the status register indicates each status of which floppy disk drive (10) using 8 bits.

D t (No.
The n-DMA Data Request (Non-DMA Data Request) flag is used for handshaking purposes when transferring data with an external system, ie, a host computer (1). This D7 flag is
It becomes "1" each time data transfer becomes possible, and the data is set to "1".

- during data transfer, it becomes "0", and when one byte of data transfer is completed, it becomes "1" again, and the inversion is repeated until the predetermined number of data transfers is reached.

The Da (No Media) flag of the next Ds bit indicates the installation status of the floppy disk (21). When the floppy disk (21) is not installed or when the eject button is operated while it is installed, It becomes "1" when the floppy disk (21) is pulled out.

Next D5 bit D s (Media Chang
e: Medium exchange) flag indicates the floppy disk (21
) may have been replaced. This indicates that the floppy disk (21) may have been replaced at reset, or when the ejected floppy disk (21) is not installed, or when the floppy disk (21) is removed by operating the eject button while it is being installed. ) becomes "1" when the flag is extracted, and returns to "0" when the next data is correctly read from the floppy disk (21).

Next D4 focus (Write Protec
t:v# write protection) flag indicates that writing to the floppy disk (21) is prohibited.When a floppy disk (21) that is write-protected is installed, and when the floppy disk (21) is not installed. When not, it becomes rlJ, and becomes "0" when a writable floppy disk (21) is installed.

Next D3 bit and D2 bit D3(ECCErr
or (error) (MSB)) flag and D2CE
CCError (Error) (LSB)) flag is
During the error detection and correction process automatically executed by the error correction processing section (15) in conjunction with the read process, the type of error that has occurred is indicated by four states using two bits.

Next D1 bit 01 (Drive Error:
The Drive Error) flag indicates a drive malfunction and indicates a drive malfunction.
1'', and the state of rlJ is maintained until the next read/write/erase is normally executed or until the above reset command is accepted.

Then, the lowest Do bit I) 6 ((:om
The mandBusy (in command) flag indicates the execution status of commands other than the reset command.
", and returns to "0" upon completion of the process.

[Command register]

All command data for controlling the floppy disk device (10) is given to the command register, and is specified by setting bits corresponding to each basic function to rlJ.

The microprogram control unit (12) interprets the contents of 1-byte command data given to the command register in the host computer (1), and executes the instruction execution unit (14).
) to automatically execute data erasing, recording, or reproducing operations in a predetermined sequence.

The most significant bits D7 and D6 of the command register contain the drive specification command (UnitSelect).
t (Unit Select) 1. Unit 5
olect (unit select) 2) is given. This 2-bit drive designation command allows you to designate up to four drives.

The next D5 bit contains an execution prohibition command (Exe-cu
tion Inhibit) is given. By setting this D5 bit to rOJ, the functions specified by the lower D4 to DO bits are disabled. When performing processing that involves execution, the D5 bit is set to rlJ.

Further, the D bit is given a command (Mon: Motor On) that instructs the rotation of the spindle motor (23). Spindle motor (23
), rotation is performed by setting the D4 bit to "1". In addition, the spindle motor (23) sets the D4 bit to “
0", it will stop after a predetermined time. Further, the magnetic head (20) moves from the home position to the outermost circumferential side as the spindle motor (23) starts rotating, and returns from the current position to the home position as the spindle motor (23) stops. Note that the D4 bit is set to “1” during normal read/IF write/erase operations.
”, the microprogram control unit (12) automatically starts rotating the spindle motor (23) in response to read/write/erase processing even if the D→ bit is “0”. However, it is configured to stop after a certain period of time has passed from the time the processing is completed.

The next D3 bit is used for data transfer (Data Tr-
answer) command is provided. By setting this D3 bit to "1", data is transmitted and received between the floppy disk drive (10) and the host computer (1). Data is sent and received by sequential transfer to the buffer memory (13) via the data register. In this case, the number of data to be transferred can be selected from 4 bytes, 512 bytes, or 256 bytes, and an in-byte address can be specified for each 4 byte.

The buffer memory (13) can also be used as a temporary bank memory of the host computer (1), independent of the operation of this floppy disk drive (IO), and is limited to 4 to 4 byte physical sector units. Instead, it can also be accessed in logical sector units of 512 bytes or 256 bytes.

The next D2 bit is given an erase (BR) command. By setting this D2 focus to "1", erasing is performed in units of physical sectors specified by the parameter register.

The next D1 bit is written (WR: Write
) commands can be given. By setting the D1 bit to "1", writing is performed in units of physical sectors specified by the parameter register. Furthermore, when an index is specified in the parameter register, an index signal is recorded. Here, in response to the write (row) command, the microprogram control unit (12) performs processing according to a predetermined sequence for writing data to the floppy disk (21), and performs processing according to a predetermined sequence to write data to the floppy disk (21). The subcode data/heragu information is automatically generated by the error correction processing unit (15),
The output is performed sequentially according to a predetermined format.

Note that the write (WR) command allows data transfer/
A series of erasing/writing operations can be executed, and the microprogram control section (12) automatically performs the processing according to a predetermined sequence.

For the next Do focus, read out RD: R'en
d) A command is given. By setting this Do focus to "1", reading is performed in units of physical sectors specified by the parameter register. Note that if an index is specified in the parameter register, it will be invalid and a drive error will occur in the status register. here,
The program control unit (Read RD) command causes the program control unit (
12) performs processing according to a predetermined sequence for reading data from the floppy disk (21), and simultaneously reads signals from the floppy disk (21) and reads data from the buffer memory (12) according to a predetermined format.
13) The error correction processing unit (15) performs error data detection/correction processing on the data read above.

In addition, the data transfer of the reproduced data from the floppy disk (21) to the buffer memory (13) and the data transfer from this buffer memory (13) to the host computer (1) can be executed using the read (RD) command. , a microprogram control unit (12) automatically performs processing according to a predetermined sequence. Furthermore, if the reading is completed normally, the reproduced track/sector number is written into the parameter register.

[Parameter register]

Furthermore, the parameter register can be read/written/erased in physical sector units or tracks (-4 sectors).
Track/sector number, sector and track mode discrimination data, buffer memory (13
), parameter data for specifying the memory area number, erasing in units of tracks, and writing of the index signal are given. This parameter register consists of 5 bytes, and the register pointer advances each time one byte is read or written.
Alternatively, when the writing of the second byte is completed, if access is continued, the pointer returns to the first byte. Note that the input register returns to the first byte when a register other than this parameter register is accessed, and the input order of the parameter registers is initialized.

The first byte of the parameter register specifies the physical sector address that involves read/write/erase processing, and the virtual logical sector address that transfers data between the buffer memory (13) and the host computer (1).
It is used as a sector register for specifying logical sector size selection, index writing, and track erasing. This sector register selectively specifies three types of logical sector sizes using the most significant two bits (Dy, DG), and also specifies writing of an index and erasing an entire track (1, 1). , the most significant two bits (Dt,
By setting DG) to (1, 1) and giving a write/erase combination command to the command register, the microprogram control unit (12) erases the entire track and then writes the index signal. By writing the index signal to the floppy disk (21), the floppy disk (21) can be accessed in physical sector units from now on.

The next 2 bits (D5.D4) specify the physical sector address of byte 4, and the value becomes valid when the read process is performed normally. 1) (Verification with the physical sector address specified in step 11 can be performed.Then, the lowest 4 bits (D).

D2. DL, Do) specifies a logical sector address in units of 512 bytes.

Further, the second byte of the parameter register is used as a trunk register for specifying a trunk number. In this track register, if the read process is performed normally, the lower 7 bits are the trunk number (1 to 50).
), and the track address set by the host computer (1) (JIJ) can be checked as needed.

The third byte of the parameter register is sector mode and trunk mode discrimination data (rOJ).

1 bit (D7) as "1") and 3 bits (Ds, Dll, D4) indicating the numbers r000J, r001J, ..., rloOJ of memory areas (13A) to (13E) of the buffer memory (13). )and,
Lower 4 reserved bits (D3, D2, Dt
, Do).

Furthermore, the 4th and 5th bytes of the parameter register contain a 2-byte copy protection code (CPC).
y Protection Code) is given.

[Data register]

Furthermore, the data register is used when transferring data between the floppy disk drive (10) and the host computer (10), and is used to transfer data between the program (PR).
O) It supports both transfer and DMA transfer, and in either case, data is transferred via this register.

Operation of G2 Floppy Disk Drive Next, the operation of the floppy disk drive (10) will be explained with reference to the flowchart of FIG.

First, the Ds (Mon) bit, D2 (ER) bit, and
It is determined whether “1” is set in either the Dl (WR) bit or the Do (RD) bit (step 1), and the determination result is rYJ (−rYEsJ
), it is determined (step 2) whether or not the floppy disk (21) is installed.The determination result of step 2 is rYJ, that is, the floppy disk (21) is installed.
1) is installed, in the next step 3, it is determined whether the control microcomputer (μCOM") of the mechanical deck system controller (19) is in the middle of a processing operation, and the control Microcomputer (
When μCOM) is released from processing operation, it is determined whether the D2 (ER) bit, Dl (WR) bit, or Do (RD) bit of the command register is set to "1" (step 4). Then, the determination result of step 4 is erased (BR) and written (WR) by rYJ, that is, the host computer (1).
) or read RD), the Dv, D+, and bits of the command register are used to determine whether or not a drive has been specified (step 5), and if the own drive has not been specified, the is the disk surface number (5IIRF#) and drive number (DR
#) and the motor-on signal (Mon) to the mechanical deck system controller (MD) (19), then (
Step 6), the next step 7 is the control microcomputer (I9) of the mechanical deck system controller (I9).
After the control microcomputer (μCOM) is released from processing, it mechanically reads the track number (TR#) set in the parameter register. System controller (HD) (19) (Stellaf 8) If the judgment result in step 5 is rYJ, that is, drive is specified, immediately proceed to step 8 and mechanically select the track number (TR#). In the next step 9, it is determined whether the Do (RD) bit of the command register is set to "1" or not, and the determination result in step 9 is rNJ. (-rNOJ) In other words, if no read operation is specified,
After transferring the data given to the data register to the buffer memory (13) (step 10), in the next step 11 it is determined whether the DL (WR) bit of the command register is set to "1". If the determination result in step 11 is rYJ, that is, a write operation has been specified by the host computer (1), the next step 12 is to write the first byte of the parameter register, that is, the Dma and Ds bits of the sector register. It is determined whether or not index writing has been specified by looking at the index. If index writing has not been specified, the process moves to step 13 and an error is detected regarding the data written to the buffer memory (13). Parity encoding processing CE in the correction processing unit (15)
NC) is performed, and in the next step 14 it is determined whether the 02 (ER) bit of the command register is set to "1". Note that if the determination result in step 12 is that rYJ, that is, an index write designation has been made, the process immediately moves to step 14, where it is determined whether or not an erase operation has been designated in the host computer 1; The judgment result of 14 is r
If YJ or erase operation is specified,
An erase operation (ER) and a write operation (WR) are performed (step 15), and if the erase operation (ER) is not specified, only the write operation (WR) is performed (step 16); If the determination result in step 11 is rNJ, that is, no recording operation is specified, only the erasing operation (1!R) is performed (step 17).
. Then, when step 15, step 16 or step 17 is performed, the status register Do (Comvaand Bus
After confirming the completion of the operation in step 15, step 16, or step 17 by looking at the flag, proceed to the next step 19 to determine whether "1" is set in D4 (Mon) of the command register. (step 19), and if the determination result in step 19 is rNJ, in the next step 20, the control microcomputer (μCO) of the mechanical deck system controller (19) is
When the control microcomputer (μCOM) is released from the processing operation, the disk surface number (5IJRF#), drive number (DR#) and motor off are determined. Signal (Moff
) to mechanical deck system controller (MD) (1
9) (step 21), and enters a standby state (step 22).

If the determination result in step l is "N", that is, the host computer (1) does not instruct the operation of the floppy disk drive (10), the process moves to step (23) and the mechanical deck system controller (1)
9) The control microcomputer (μCOM) determines whether or not the processing operation is in progress, and when the control microcombiator (μC0N) is released from the processing operation, the disk surface number (5URF#' ), drive number (DR#), and motor off signal (Moff) to the mechanical deck system controller <MO) (19) (step 24), perform data transfer (step 25), and wait in step 22. state. Also, if the determination result of step 4 is rNJ, that is, the host computer (
1) Specify the rotation of the spindle motor (23) (M.n
) has been performed and the erase operation (ER), IF write operation (WR), and read operation (RD) have not been specified, the process moves to step 26 and the disk surface number (SURF#) and drive Number (DR#) To I
After giving the E-off signal (Mof f) to the mechanical deck system controller (MO) (19) (step 24), the data transfer in step 25 is performed. 21) is not installed, the process moves to step 27 to determine whether a drive has been specified, and if the driver has been specified, the process immediately proceeds to step 2.
2, and when another driver is designated, the process moves to step 2o.

Furthermore, the determination result in step 9 is rYJ, that is, the read operation (RD) is performed by the host computer (1).
If it has been determined that
(Step 29).

Then, when the data read operation in step 29 is performed,
In the next step 30, paste the status register.

After checking the (Cos+a+and Busy) flag and confirming the completion of the operation in step 27, proceed to the next step 31.
, the D1 bit of the status register is checked, and in step 29 it is determined whether the data has been correctly sent to the target track of the magnetic head (20) and the data read operation has been performed normally.If there is no drive error, the , the error correction processing unit (15) performs error correction processing (DEC) (step 32), and in the next step 33, it is determined whether there is an error that cannot be corrected by the error correction processing of step 32, and if there is no error. If the trunk number (TR#) and sector number (SC#) included in the subcode data (5OB-GODH) of the read data are
) and copy protection code (CPC) to the parameter register (step 34), and subcode data (
5OB-CODE) is detected (step 35), and subcode data (5OB-CODE) is determined (step 35).
), if there is no error, the buffer memory (13)
After the process of step 36 is performed, in which the data read out in step 1 is transferred to the host computer (1) via the data register, the process moves to step 19.

Note that step 31, step 33, and step 35
If the determination result is rYJ, that is, an error has occurred, the process immediately moves to step 19.

In the floppy disk drive (10) of this embodiment, command data (D?, Da, D5, D4) is given to the command register of the interface circuit (11) by the host computer (1).

D3+D2+D1+Do) is interpreted by the microprogram control unit (12) and performs various series of control operations as shown below.

[Control operation example 1] Command data (mouth T 10!1 +Ds 10410
3102101100 ) (1) Spindle motor on (2) Magnetic head feed (seek) (3) Erase operation (4) Write operation (5) Spindle motor off (6) Magnetic head feed (caliber plate) [Control operation example 2] Command Data (Dv, Da, 05, U4.D3
, D2, D□, Do) (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?, Us, D5.D4, Dl
, 02 , Os , Do ) - (OO110110) (1) Spindle motor on (2) Magnetic head feed (seek) (3) Erase operation (4) Heat-up operation [Control operation example 4] Command data (Dv 10G 1051041031
02 +Di +Do ) Wrinkle (00100001) (11 Spindle motor on (2) Magnetic head feed (seek) (3) Read operation (4) Spindle motor off (5) Magnetic head feed (caliber plate) [Control operation example 5] Command Data (D? +Ds +Ds 104103
102, Dl, Do) (11 Spindle motor on (2) Magnetic head feed (seek) (3) Read operation (4) Data transfer Here, command data (Dv, Ds, Ds
.

D4.03. D2. For example, (001
0110) is sent to the host computer (
An example of a control operation when the command register 1) is applied to the command register of the interface circuit (11) will be explained in detail.

The microprogram control unit (12) interprets the command data (0010110) and serially transfers the rotation command signal (Mon) and trunk number (R#) of the spin motor (23) from the instruction execution unit (14). and gives it to the mechanical deck system controller (19). Then, in response to the rotation command signal (Mon) and the track number (TR#), the mechanical deck system controller (19) starts the spindle motor (23) and drives the floppy disk (21).
At the same time, the feed motor (22) moves the magnetic head (20) to the specified track number (TR#).
While moving to the position, the microprogram control section (
The host computer (1) transfers the data to the buffer memory (13) via the data register of the interface circuit (11) when the host computer (12) notifies that it has accepted the data transfer and is ready. In addition, the mechanical deck system controller (19) is connected to the spindle motor (23).
When the rotation of the magnetic head (20) is stabilized, the movement of the magnetic head (20) is completed, and the command execution unit (14)
Let me know. Furthermore, the error correction processing unit (I5) is configured to transfer data from the host computer (1) to the buffer memory (11).
Generate error correction parity for the data transferred to the Then, the microprogram control section (12
), the mechanical deck system controller (19) notifies the command execution unit (14) of the completion of recording preparation, and
When parity generation is completed by the error correction processing unit (15), wait until the floppy disk (21) rotates to the start position of the target sector, operate the recording circuit and erase circuit, and erase with the advance erase head. data is recorded using the recording/reproducing head. Furthermore, the microprogram control unit (12) receives a motor off signal (Mof) from the instruction execution unit (14) for the spindle motor (23).
f) is given to the mechanical deck system controller (19) by serial transfer to stop the rotation of the spindle motor (23) and notify the host computer (1) of the completion of the data recording operation.

Regarding the operation method related to the G3 buffer memory, the operation related to the buffer 1 memory (13) will be explained with reference to FIG. As mentioned above, the buffer memory (13) has five memory areas (13A) to (13
It is made up of 2 memory cells, each with a capacity of 6 bytes. Note that the 2-byte spare area in the buffer memory (13) is not shown.

This buffer memory (13) is controlled by the host computer (1) via an interface circuit (11) and a microprogram control section (12). Played from a floppy disk (21), recording, playing,
Data supplied via the erase circuit (1B) and data recovery circuit (17) is written to the buffer memory (13), error corrected by the error correction processing section (15), and the error corrected data is read out. and is transferred to the host computer (1) via the interface circuit (11).

As mentioned above, the host computer (1) sends the track number (7 bits) and sector number (2 bits) as well as the memory area number (3 bits) to the parameter register of the interface circuit (11). , (13B).

(13G), (130), (13E) robot, roolJ, roto
r, rollJ.

rloooJ), sector mode and track mode discrimination data (1 bit) are set therein.Based on these data, the buffer memory (13) is controlled by the microprogram control section (12).

First, the case of track mode (when the discrimination data is "1") will be explained. The magnetic head (20) is moved to the track to be reproduced. Magnetic head (20)
After the index signal of the trunk is reproduced, the floppy disk (21) rotates one more time, and then 4 sectors worth of data from that track is reproduced.After the reproduced data is demodulated, it is transferred to the buffer. Memory area (13B) to (13B) of memory (13)
) is written to. The four sectors of data are error-corrected sector by sector by the error correction processing unit (15) and then transferred to the host computer (1) via the interface circuit (11). A similar operation is performed for the other trunks of the floppy disk (21), and the contents of the memory areas (13B) to (13B) are rewritten with the data of the four sectors of that track, error correction is performed in the same way, and the host computer Transferred to (1). In this track mode, data in the four sectors of the track are always stored in memory areas (13B) to (13E).
) is written to.

On the host computer (1) side, the memory area (13
It manages track numbers of data stored in B'') to (13B).

When data such as programs is recorded in track units on the floppy disk (21), the data is played back in trunk units and written to the buffer memory (13), and the error correction processing unit (15) corrects errors in each sector. After correction, the data is transferred to the host computer (1) via the interface circuit (11), thereby reducing data processing time.

Next, the case of the normal mode of the sector mode (when the discrimination data is "0") will be described. Magnetic head (20)
is moved to the track to be played. After the index signal of a desired track is reproduced by the magnetic head (20), the floppy disk (21) rotates one more time, and then data for one desired sector of that track is reproduced. After the data is demodulated, the memory area (13A) of the buffer memory (13)
will be written to. The data for one sector is error-corrected by the error correction processing unit (15), and then sent to the host computer (11) via the interface circuit (11).
1). Similar operations are performed for other sectors of the floppy disk (21), and the memory area (
13A) is rewritten with the data of that sector, similarly error corrected, and transferred to the host computer (1).

In the normal mode of this sector mode, the data of that sector is always written to the memory area (138). On the host computer (1) side, the memory area (13A
) manages track numbers and sector numbers of data stored in the memory.

Furthermore, the case of the special mode of the sector mode (when the discrimination data is "0") will be explained. Magnetic head (20)
is moved to the track to be played. After the index signal of a desired track is reproduced by the magnetic head (20), the floppy disk (21) rotates one more time, and then data for one desired sector of that track is reproduced. After the data is demodulated, for example, the memory area (1) of the buffer memory (13) is
3A). After the l sector worth of data is error corrected by the error correction processing unit (15),
It is transferred to the host computer (1) via the interface circuit (11). The playback data from other sectors is stored in the next memory area (13) of the buffer memory (13).
B) Write and reproduce data from separate sectors as well in the memory area (13C).

(130), (13E), (13^),・
. . , one after another, and errors are corrected for each one.

In this case, the host computer (1) is provided with a pointer indicated by a triangle in FIG.
After writing data to the memory area (13
The pointer corresponding to number C) is moved to correspond to the number of the next memory area (130). And this pointer is the memory area (13^),
(13B) ,..., (13B).

(13A), . . . are sequentially and cyclically moved to the corresponding numbers. In the host computer (1), each memory area (13^) of the buffer memory (13)
) to (13E), the track number and sector number of the data stored in that memory area are managed as headers, and the error-corrected data stored in the memory area is managed by the host computer (1). The data of the memory area number from 1 to 1 is transferred to the interface circuit (11
) to the microprogram control unit (12), data in a desired sector of a desired trunk stored in the buffer memory (13) can be transferred to the host computer (1) any number of times. Ru. In this case, the data does not need to be error-corrected again and is immediately transferred. As a result, the host computer (1)
When attempting to repeatedly use data in a certain sector of a trunk on a floppy disk (21), the waiting time from the time the data is played back by the magnetic head (20) until it is imported into the host computer (1) is significantly increased. be shortened.

Note that even in the normal mode of the sector mode, when the host computer (1) uses a pointer, the pointer may be fixed to the number of the memory area (13A).

In this way, the buffer memory (13) is provided with memory areas (13A) to (13E), and the floppy disk (
21), the recorded data is reproduced track by track or sector by sector, demodulated, and then stored in the buffer memory (13).
Since errors are corrected, the processing time for continuous long data in track units is shortened, and short data in sector units can be processed in the same way as before, and is transferred to the host computer (1) many times. Since the data can be stored in the buffer memory (13) until its use is finished, the processing time for the data can be shortened.

Note that the number of memory areas of the buffer memory (13) can be modified in various ways, such as for a plurality of sectors, for a plurality of tracks, etc.

Also, the memory area (13^) of the buffer memory (13)
) ~ (1311 number, its memory area (13A)
Since the host computer manages the track number and sector number to which the data stored in (13B) belongs, the management and buffer memory (13)
This makes it easier to control. Incidentally, this management and control is performed by ADC.
(Advanced disk controller) [In particular, its instruction execution unit (14)] could consider managing it, but that would put a heavy burden on the ADC side.In that case, the memory area (13A) of the buffer memory (13)
)～(131 number, its memory area (13A)～
(The trunk number and sector number to which the data stored in the buffer memory (13
) or other memory.

G4 Data Recording Format Next, the data recording format of the 2-inch floppy disk will be explained with reference to FIGS. 4 to 9.

[Track Format J The track format is shown in Figure 4. One track is:
It consists of an index and four sectors, sector #0 to sector #3. ■The trunk is created sequentially from the data start position, gap 0 (prefix index gap)
, Index, Gap 1 (Post Index Gap), Sector #0: Gap 2 (Sector Gap), Sector #1, Gap 2 (Sector Gap), Sector #2, Gap 2 (Sector Gap), Sector #
3. Consists of Gap 3 (Final Gap). The index is a continuous T raax signal. Incidentally, the IF (frame) consists of 44B (pi, day), and the IB consists of 10 channel bits.

Sector nature of each track of floppy disk (21) is 0
~The boundaries of the four sectors of sector #3 coincide in the radial direction. PG is a rotational phase detection signal generated in response to the rotation of a spindle motor that rotationally drives the floppy disk (21), and is associated with an index.

C sector format] Figure 5 shows the sector format. One sector consists of sequential preamble data "?B", synchronization frame, subframe, coding data (data frames 0 to n
-127) and postamble “2B”, 57
Make a length of 65B.

[Frame format]

The frame format is shown in Figure 6, and the l frame is:
11 of sequential sync 1, sync 2, E, P, S, (frame pre-sync) and parity set (4B (B-byte))
It has a length of 44B.

[Zub frame format]

FIG. 7 shows a subframe former 7). One subframe consists of sequential synchronization, sub, frame address, parity, mode, track number, and sector number (0#, 1#
, 2#, 3#), head number, copy protection, reserved area, and C1 parity (4 symbols), and has a length of 44B.

[Data frame format]

FIG. 8 shows the data frame format.

One data frame consists of sequential synchronization, sub, frame address, parity, coding data (32 symbols), C2 parity (4 symbols), and C1 parity.
(4 symbols) and has a length of 44B.

[Subcode]

FIG. 9 shows the subcode. The Cobb code has 128 subdata in the data frame. The subcode assembly consists of subcodes #0, #1, #2, and #3. One subcode consists of sequential mode, trunk number, sector number, head number, copy protection, reserved area, C1 parity (4 symbols), and has a length of 32B.

Formation of G5 Parity Next, the formation of C2 parity and C1 parity by the error correction processing section (15) will be explained with reference to FIG. It should be noted that FIG. 10 shows data frames involved in the formation of C2 parity and C1 parity and subframes involved in the formation of CI parity among the data constituting the l sector. C2 parity (
The error correction code (error correction code) is formed by interleaving a plurality of C2-series symbols (coding data) extending from the upper left to the lower right in the figure among a plurality of symbols arranged in a matrix. Further, the C1 parity (error correction code) is formed from a plurality of symbols (frame address, coding data, and C2 parity) of the C1 series extending vertically from the top to the bottom in the figure. Note that for the subframe, only C1 parity is formed. For example, a Reed-Solomon code is used for the C1 parity and the C2 parity. In addition, the subcodes in the data frame are divided into 4 subcodes with the same content in the horizontal direction in the figure over 128 frames.
A subcode sco''sc3 is formed.

Map of Gs memory area Next, buffer memory during data playback (13)
The map of memory areas (13A) to (13E) of
As mentioned above, this memory area shown in Figure 1 has a capacity of 6 bytes (= 6144 bytes = 128 x 48 bytes), and the coding data for 128 frames (1 sector) is 32 x 48 bytes on the left side of the figure. Written in a 128-byte area. Also, C2 parity and C1
Parity is written in each 4×128 byte area adjacent to the area where coding data is written. A read flag indicating when data is written and a CI correction flag according to the result of error correction No. 11 using C1 parity are written in an area of 1×12B bytes at the right end in the figure. The read flag and 01 correction flag are set for each frame, and the read flag and 01 correction flag for each frame are written in the same byte (8 bits).

Also, the frame address is lX1 adjacent to this area.
Written in a 28-byte area. Furthermore, subcodes 5CO to 5C3 having the same content are written in an I x 128 byte area adjacent to the area where the frame address is written. Also, of the 128-byte area adjacent to this area, the upper 4-byte area in the figure is used to set a correction flag based on subcode parity, and the lower 7-byte area is used for error correction processing. Department (
15) is used as an internal register. Note that the shaded area in the figure is an unused area.

H Effects of the Invention According to the present invention described above, there is provided a magnetic disk that can reproduce data from a magnetic disk in units of sectors or in units of tracks, and can shorten the waiting time when reproducing the data in units of tracks. A driving device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a floppy disk drive to which the present invention is applied, FIG. 2 is an explanatory diagram showing a buffer memory thereof, and FIG. 3 is used to explain the operation of the floppy disk drive shown in FIG. 1. Flowchart, Figure 4~
FIG. 9 is an explanatory diagram showing the data recording format of a floppy disk, FIG. 10 is an explanatory diagram of parity formation, and FIG. 11 is an explanatory diagram showing a map of the memory area of the buffer memory. (1) is a host computer, (10) is a floppy disk drive, (11) is an interface circuit, (
12) is a microprogram control unit, (13) is a buffer memory, (13A) to (13B) are memory areas, (
14) is an instruction execution unit, (15) is an error correction processing unit, (
16) is a data transformation circuit, (17) is a data demodulation circuit,
(18) is a recording/reproducing/erasing circuit, (19) is a mechanical deck system controller, (20) is a magnetic head, (2
1) is a floppy disk, (22) is a head feed motor, and (23) is a spindle motor.

Claims (1)

[Scope of Claims] The invention includes a buffer memory in which data reproduced from a magnetic disk, each track of which is composed of a plurality of sectors, is stored, and an error correction processing section that performs error correction processing on the data stored in the buffer memory. In the magnetic disk drive device, the buffer memory has a capacity to store data for at least one track of the magnetic disk, and the buffer memory stores data reproduced from the magnetic disk in either track units or sector units. Store in buffer memory,
A magnetic disk drive device characterized in that the error correction unit performs error correction.