JPS6152732A - Disc controller - Google Patents

Abstract

PURPOSE:To diagnose easily the synchronous byte detecting capability and hard information check functions by adding a false AM generating circuit. CONSTITUTION:Test records are written in fields 401-408 of a data format, and an AM is written on the field 401. A byte number GL from the index to the field 401 is set to a register 302. The diagnostic mode is set, and records are read in order from the AM, and a test data part 201 and a block check code 202 are read to perform block check. When reading advances to the field 401 thereafter, contents of a byte position counter 301 and the register 302 coincide with each other, and a flase AM detection signal goes to ''1'', and a controller searches a synchronizing byte and performs hard information.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention provides a synchronous byte detection capability of a disk controller;
This relates to a circuit for diagnosing block checking ability, etc.

[Background of the invention]

Generally, the record format of a disc is AM, as shown in Figure 1.
, gap, synchronization byte, hard control information, record control information, block change code, gap, synchronization byte, data, block check code, and gap.

The ability to detect synchronization bytes, the ability to check hardware control information, the ability to check or correct data using a block check code, etc., has conventionally been performed using the K, middle K of data, data to be tested, and block check code as shown in Figure 2. By writing the data length and controlling the data length according to the length of the data to be tested, the invalid data written as test data is read out, and the book check circuit is activated to check its performance. was taken.

However, with this method, /'IM, which is a special recording method, cannot be written as part of the data, so AMK Tsuzu (synchronous byte detection ability, hardware control information (cannot be written during data transfer), IC There was a drawback that it was not possible to diagnose the checking ability by

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a circuit that eliminates the above-mentioned drawbacks and makes it possible to diagnose the ability to check synchronization bytes and hard control information.

[Summary of the invention]

The present invention generates a special recording format AM in a pseudo manner when a preset register value matches a byte position counter value from an index, and records the point of occurrence in the data. In addition, it is now possible to evaluate the detection ability by reading the second half of the test record, which is set between test records and makes some of the synchronization bytes and hardware control information invalid values. This is what I did.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be explained in more detail with reference to FIG.

501 is the byte position counter from Inter Sox, 5
02 indicates AM occurrence position 1/gister and is set by the % control device. In 505, when the comparison circuits 501 and 502 match, the output 504 becomes 1. The signal 504 is
The diagnostic mode signal 506 is input to the D circuit 505 and becomes 1.
So, when the AM search signal 507 is 1, the normal AM
When ORed with the detection signal 508 as a conventional AM detection signal, the controller enters into operation looking for the sync byte. On the other hand, the data format at this time is shown in FIG. 40
Test records are written from 1 to 408.

401 is the position where AM is to be written, and the content to be written may be the same as the gap, but the number of bytes GL from the index to 401 is set in the register 502.

When a test record with invalid hardware control information 404 is written, the read operation is as follows. First, GL
Set the value to 502, enter the diagnostic mode, read the records in order from AM, read the test data section 201 and block check code 202, and perform a block check. After that, when reading continues up to point 4010, 501
When the circuits 502 and 502 match, the pseudo AM detection signal becomes 1, and the control device performs a synchronization byte search.

After that, the hardware information is checked, but because the value is invalid, it is treated as an error, and the same test record is usually read again by retrying the command.

At that time as well, the same record is read and checked using the pseudo AM generated at position 401.

Next, a second embodiment of the present invention will be shown.

This is to automatically set the pseudo 4M position,
Normal gap between records 108. , 410 are fixed, the output of the gap counter 501 is decoded by the decoder 502, and when the value reaches a certain value, the value of 501 is set in the register 504 at the button timing T1. It is.

〔Effect of the invention〕

According to the present invention, by adding a simple pseudo AM generation circuit, it is possible to easily diagnose the synchronous byte detection ability and the hardware information checking function, which has been difficult in the past.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the record format, Fig. 2 is an explanatory diagram of the record format used when evaluating the checking ability of a control device using the same circuit, and Fig. 5 is an explanatory diagram of the record format used when evaluating the checking ability of a control device using the same circuit. FIG. 6 is a diagram of a pseudo AM generation circuit according to another embodiment of the invention.

Claims (1)

[Claims] 1. Special recording format section (AM) indicating the beginning of the record
The start of a track (
It consists of a counter and register that counts the number of bytes from the index), a circuit that compares the values of the counter and register, and a circuit that ORs the match signal with the AM detection signal in diagnostic mode, and stores it as data in the record. The start position of the written second record is set in the above register, and the synchronization byte, hardware control information, block check code, etc. generated by the hardware are arbitrarily given as data from the outside. A disk control device characterized in that it is possible to diagnose a synchronous byte detection circuit, a hardware control information check circuit, a block check circuit, etc. by detecting and reading an output from the comparison circuit in a diagnosis mode. .