JPS583115A - Final recording confirming system - Google Patents

Abstract

PURPOSE:To prevent missing of recording and data, by comparing the contents of the final recording with that of verification written at the recording in advance, in confirming the final recording. CONSTITUTION:A modulation and demodulation circuit 14 has functions that byte conversion of bit serial from a signal line 100 is performed and the signal is shifted to a buffer register 15 at reading and a data in byte unit from a channel 2 is inputted from the register 15 and written in a disc device 3 with bit serial conversion at writing. An AM detection and forming circuit 13 detects and forms the AM based on a command 101. The said detection and forming are made on signal lines 102 and 103. Count buffers 16 and 17 writes and stores the count field based on a command 104 at each reading of the recording of a track at reading and at each forming of record at write. The data in the count buffers 16 and 17 are inputted to a comparison circuit 18.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a final record confirmation method for a rotating external storage device such as a variable length record type magnetic disk or magnetic drum.

A magnetic disk device will be described below as an example of a rotating external storage device.

Figures 1 to 3 show the track format in a normal magnetic disk drive, where the track starts and ends at index Mars I, and the home address (HA) and record (Ro = Rn). 1" is written. HA and Ro are different from other records, and writing to these parts is done under certain restrictions. HA and each record are separated by gaps, especially when writing from index to HA.
The definition of the G4 gap is not specified because it has 91 gaps from the end of the last record to the index row, but the G4 gap in the present invention is defined as the start of the index row from the end of the last record to the index row. It consists of three fields, 0, which is the area from 1 to 0 to the trailing edge. (Figure 2) Key.

User data is written in the data field. Further, the characteristics of the record are described in the count field.

The three fields of the record are also separated by a G2 gap.

The count field further has a function as shown in FIG. Following AM is a count field with a fixed length of 12 bytes. This includes the cylinder number where the record is written, the track number (head number), the record number within the track, the key length of the record, the OAM format in which the record length is written, the number of bytes in the count field, and the gap. The length is determined unique to the disk device.

To create a 0 record, which will be explained next about record processing, the WRITE CKD command field is
-Chain after executing 5EARCH commands for IA. The 5EARCH series command has a function of sequentially comparing the contents of the count field prepared by the software with the contents of the count field on the medium and, when all matching records are found, reporting the fact in the status byte of the command.

There are two ways to read and write records.One is to use the command (READIIA) that positions the record once.
After issuing 5EARCT(-T(A), execute the 5EARCI(type command) in the count field of the target record.Other method is to immediately issue the 5EARCf(type command, and first execute the nearest This method performs 5EARCH processing from the recorded records.
H is performed and the count field following the first detected AM is processed. It's up to you, so it's AM
5EARCH is not performed.

In the conventional record processing method described above, there was a problem in the way the final record was stored. In other words, in the past, when a predetermined record was processed, and when trying to process subsequent records, it was detected that no record existed there, , Recognizes that the last processed record was the last record.O When it is recognized that the last record is the last record, it is unconditionally positioned at the index mark and the subsequent processing is performed.

At this point, the device (magnetic disk unit, magnetic drum unit, etc.) has degraded characteristics of the modulation/demodulation circuit, and the record detection ability has deteriorated due to scratches on the recording medium. Omissions, data omissions, etc. occur.

An object of the present invention is to prevent record omissions, data omissions, etc. by detecting the aforementioned erroneous recognition of the final record.

Q4- Also, the object of the present invention is to store the contents of the count field of the last record in a predetermined area from the end of the last record to the falling edge of the index when creating a record in a variable-length record-type rotating external storage device. This is achieved by a final record confirmation method in which the verify record is omitted and the contents of the count field of the last read record are compared with the contents of the verify record at the time of reading.

That is, in the present invention, the final record is verified by comparing it with the contents of the verify record written in advance at the time of record creation, and if the two do not match, an error is reported, and the final record is recognized in the sensest η report. By deceiving the contents of the count field of the record and the contents of the verification record, the occurrence of record reading, the last record actually written, and the first record that was read are notified. It is something.

The record (RV) is the record (verify record) for confirming the final record mentioned above. ◎Figure 5 shows
The format of the Verify record is shown below. A Verify record consists of only a count field, has a fixed absolute position from the index mark, must be written and exists, and is a soft record. Sixth bit to prevent access from, for example the flag byte '
) is characterized in that a special code is written in it.Also, as mentioned above, the index mark has an EC code in its mark area.
The verification time is less than 20 bytes even including the C byte.
Records can be written.

In this case, it is useful because the start of the index can be used as the timing to start writing the peripheral 7 eye record. Hereinafter, with reference to the drawings, to realize the final disk confirmation method according to the present invention An embodiment of the disk control device and its operation will be described.

Firstly, the main circuit configuration of a -1 type disk control device to which functions according to the present invention are added is shown. In the figure, 1 is a disk control device, 2 is a Hiro channel, and 3 is a disk device (
◎The control device 1, which is a device), is connected to the channel 2 via the channel interface control section 11.

The control device 1 executes channel commands under the control of the microprogram control section 2, and performs connection, read/write, and disconnection with the disk device 3.

Hereinafter, only the operation of the main circuit according to the present invention will be explained.

In a read operation, the modulation/demodulation circuit 14 converts the bit serial data sent via the signal line 100 into bytes and moves it to the buffer register 15, and in a write operation, it converts the byte unit data sent from channel 2 into one buffer register 15. It has the function of converting the input into bit serial data and writing it to the disk drive [3].

The AM detection and creation circuit 13ti detects and creates an AM (address mark) based on the command 101 of the microprogram 7-. Here, the above detection and creation are performed by signal lines 102 and 103.

The count buffers 16 and 17 are based on the microprogram command 104, and when reading, the count field is overwritten and stored every time a track record is read.When writing 0, the count field is overwritten and stored every time a record is created. overwrite and store.

In addition, the two count buffers 716 and 17 are connected to the comparison circuit 18.
In the following, examples of the final record confirmation method according to the present invention will be explained separately for the time of record creation and the time of read, along with the operating principle of the circuit configuration unique to the present invention.

(1) When creating a record ■ When the channel interface control unit 11 receives a command from the channel, it notifies it to the command decoding unit 20 via the signal line 105. ■ The command decoding unit 20 issues the WRI TE CKD command. When decoded, the microprogram control unit 12 is notified of this fact.

■ Micro program (Micro program control section 1
2) is active under the control of WRITE CKD
Upon receiving the notification of command reception, it instructs the timing circuit 19 via the 1% signal line 106 to write a gap write i1 for creating a new record.The timing circuit 19 is as described in FIGS. Creation of one gap, creation of fields, etc. related to the record format are performed under the control of the microphone program.

■ Next, the AM detection and creation circuit 13 is instructed to create an AM (address mark) via the microbogram LD signal line 101. ■ The AMM detection and creation circuit 13 synchronizes with the timing signal from the timing circuit 19. and υ
At the same time, it creates an AM in conjunction with the modulation/demodulation circuit 14 and notifies the microprogram.

■ When the microprogram is notified of the completion of AM creation, it instructs the channel interface control section 11 to start data transfer in write mode, and also instructs the data transfer control section 21 and timing circuit 19 to write in the count section. ◇ ■ Data sent from the channel (in this case, the contents of the count field) is sent to the channel interface control unit 11.
The data is transferred to the disk device 13 via the data transfer control unit 21 - buffer register 15 → modulation/demodulation circuit 14 and read/write line 100, but is simultaneously saved from the one buffer register 15 to the count buffer 17.

(2) When the timing circuit 19 receives notification of completion of writing of the count field via the signal line 106, the key field and data feed are subsequently read. Similarly to these write operations, the microprogram gives instructions to the channel interface control unit 11, data transfer control unit 21, and timing circuit 19, and executes the 0 key and data field input operations. At the time of writing, the data is not saved to the buffer register empty count buffer 170. When the microprogram receives the notification of completion of data field writing from the timing circuit 19, it instructs the channel interface control unit 11 to end the command. 0) Channel interface control unit 11 reports the completion status, then determines whether there is a command chain, and notifies the microprogram to that effect.

■ When the microphone four-gram receives the command chain notification, it determines that the command is the WRITE CKD command again, and if so, it returns to step ■ and returns the record creation.00 Microprogram, command chain No notification, W
When a chip-in of a command other than the RITE CKD command is detected, the timing circuit 19 and the modulation/demodulation circuit 14
The erase operation continues until the rising edge of the index is detected by the index detection circuit 22 and notified via the signal line 107.

■ When the microprogram is notified of the start of the index by the index detection circuit 22, it checks the A of the verify record using the same procedure as shown in steps (■) and (■) above.
Create M〇 [Phase] After creating the AM of the verify record, instruct the timing circuit 19 to omit the count field 0 In this case, the data to be written is the content stored in the count buffer 117 (last created (contents of the count field of the recorded record).

(1) Writing/Writing of Verify Record Count Section 12 - Upon receiving a notification of completion from the timing circuit 19 via the signal line 106, the microprogram waits for an index fall signal 108 from the index detection circuit 26.

When the index falls, if there is a command chain, it is executed, but if there is not, all processing ends.

(2) When reading ■ All record read processing starts from AM detection.

(2) When the microprogram is notified by the command decoder of the receipt of a record read command, it instructs the AM detection and creation circuit 13 to search for an AM.

(2) The AM detection and creation circuit 13 performs AM detection in conjunction with the modulation/demodulation circuit 14. (2) When AM is detected, the microprogram is notified of it via the signal line 102.

■ When the microprogram receives the AM detection notification, it instructs the timing circuit 19 and data transfer control unit 21 to read the count field, and also instructs the channel interface control unit to start data transfer in read mode. do.

■ The data read from the disk is sent to the modulation/demodulation circuit 1.
4 → buffer register 15 → data transfer control unit 21 → channel 2 via channel interface control unit 11
However, at the same time, it is saved from the buffer register 15 to the count buffer 17.

(2) When the timing circuit 19 receives a notification of completion of reading the count field via the signal line 106, the key field and data field are subsequently read. These readings are executed by giving instructions from the microprogram to the channel interface control s11, the data transfer control section, and the timing circuit 19 in the same way as reading the count field.

When reading the key and data fields, the data cannot be saved from the 1-buffer register 15 to the count buffer 17.

(2) When the microprogram receives a notification from the timing circuit 19 that reading of the data field has ended, it instructs the channel interface control section to report an end status to end the command.

■ The first AM search executed is performed without a time limit, and the first record to which AIVI is found is the target of processing, but once the count field has been processed, AM searches by subsequent commands are This is done with a time limit. In such a case, after instructing the microphone U program dW detection creation circuit to start AM search, a certain period of time (usually from the end of the data field of the previous record to the key field of the record) If there is no notification of AM detection within the time required to reach the front end, it is assumed that there is no next record.

15- ■ When it is determined that there is no next record (there are cases where there really is no record, and cases where the record is overlooked by mistake), the microprogram detects the index detection circuit 22.
Vr? Z, which instructs to detect the rise of the tL index.

■ When the index detection circuit notifies the index start-up, the contents of the count buffer 17 (the contents of the Karaite field of the record read last) are saved to the count buffer 16, and then The count field of the verify record is read by the procedure, but the contents of this record are not transferred to the channel, but are saved to the count buffer 17 via the buffer register 15. When the circuit 19 is notified via the signal line 1106, the microprogram compares the contents of the count buffer 1 and the count buffer 17 by the comparison circuit 18. This means that the last processed record was the final record of that track, so it is assumed that the code was overlooked, and processing continues.

■ When the discrepancy signal 109 is notified, it is assumed that a record has been overlooked...The channel interface control unit is instructed to report the termination status in order to terminate the command abnormally.O It is clear from the above embodiments. As shown above, in the present invention, the contents of the count field of each record are sequentially stored when creating a record, and only the contents of the count field of the last record are stored in the verify record and [when the index is set up in step 7]. During writing and reading, the contents of the count field of each record are sequentially stored by means of triggering. 2. Only the contents of the count field of the record recognized as the final record are written to the verify record. This is to compare the contents of the count field and confirm the correct final record. Therefore, according to the present invention, it is possible to prevent record omission, data omission, etc. due to incorrect confirmation of the final record, and it is possible to provide a more excellent control circuit for storage equipment.

Furthermore, in the above embodiment, a method was shown in which the verify record was written by the rise of the inductor; however, the application of the present invention is not limited to this. In other words, the fall of the inductor from the last record is h
Writing and reading of the verify record is possible in a predetermined area (G4 cap in the present invention) in 1.

In addition, although only a magnetic disk device has been described in the embodiments, as is clear from the functions of the present invention, the present invention is applicable to variable-length record type non-rotating S storage capacity. Valid for all.

[Brief explanation of drawings]

1 to 3 show the track format h in a conventional magnetic disk device; FIG. 4 shows the track format h in a magnetic disk device according to the present invention;
The figure shows the format of the verify record of the present invention, and FIG. 6 shows the main circuitry of a magnetic disk control device that implements the present invention. In the figure, ■ is a rendex, 01 to G4 are gaps on the track, AM is an address mark, 1 is a disk control unit, 2 is a channel S3 is a disk manufacturing cylinder, 11 is a channel interface control unit, 12 is the microprogram control section, 13 is the AM
Detection and creation circuit, 14 is a modulation/demodulation circuit, 15 is a buffer register, 16.17 is a count buffer 1. 18 is a stop-turn circuit, 19 is a timing circuit, 20 is a command-decode section, 21 is a data transfer control section, 22 23 is a device interface control section. Agent Patent Attorney Calculator Hiroshibu

Claims (2)

[Claims] (1) When creating a record in a variable-length record-type rotating external storage device, write a verify record consisting of the contents of the count field of the last record in a predetermined area from the end of the last record to the falling edge of the index ψKF). . A final record confirmation method, characterized in that, at the time of reading, the contents of a count field of the last read record are compared with the contents of the verify record. (2) The final record confirmation method according to claim 1, wherein writing of the verify record is started after an index is started up in an erase process after the final record is created.