JP2882245B2 - Self-diagnosis method of magnetic disk controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-diagnosis system for a read / write integrated circuit of a magnetic disk drive.

[0002]

2. Description of the Related Art A conventional writing / reading integrated circuit of a magnetic disk drive will be described with reference to an example of a write / read integrated circuit (hereinafter abbreviated as FDC) of a floppy disk drive using an MFM recording method. .

FIG. 4 shows a conventional floppy disk drive F
FIG. 3 is a configuration diagram for explaining a DC test. FIG.
FIG. 3 is a waveform diagram of an FM recording method. In FIG. 4, a floppy disk drive (hereinafter abbreviated as FDD)
The read signal is a mixture of a clock pulse and a data pulse according to the MFM recording method.
The L circuit 22 generates a separation signal (hereinafter abbreviated as WINDOW signal) for separating the clock pulse and the data pulse. The data separator 23 separates the data from the read signal from the FDD by the WINDOW signal generated by the PLL circuit 22, and transfers the data as 8-bit data via the host interface 25 by the serial / parallel conversion circuit 24. I do. At the time of writing, 8-bit data transmitted via the host interface circuit 25 is converted into serial data by the parallel / serial conversion circuit 27, and the mixer 26 converts the clock signal into a serial signal of data only. In addition, the data is output as FDD write data.

In this configuration, when a failure occurs in a device incorporating the conventional FDC, it is important to identify the failure portion, and it is necessary for the integrated circuit constituting the device to have a self-diagnosis function. Will help identify In self-diagnosis of FDC, FDD
It is important that the write signal to the FDD is normal and that data can be read from the read signal from the FDD. For this purpose, a test is performed by writing to and reading from the FDD with the FDD connected to the FDC. .

In a test using a conventional LSI tester, a read signal from the FDD is supplied by the LSI tester instead.
When the LL circuit 22 is an analog PLL circuit, there is an upper limit and a lower limit on the frequency at which a WINDOW signal can be generated according to an input signal. The read signal from the FDD becomes high speed to determine the transfer speed of the FDD data. Because the operating frequency in the test is limited to the actual FDC operating frequency due to the limit of the operating frequency of the PLL circuit 22, a self-diagnosis function is built in to reduce the exchange of high-speed signals, and only the final result is used as a pass / fail decision. Is important for LSI testers.

[0006]

When there is an inconvenience in the conventional FDC, a test is performed by connecting an FDD and actually writing and reading data to and from a floppy disk. Since it is necessary to supply the same signal as the read signal on the LSI tester side, it is necessary to always supply the read signal from the FDD to the outside even if the self-diagnosis function of the FDC is added, and the FDC alone Can't test, LSI
Testers have the disadvantage that they must always be tested at the actual operating frequency.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned drawbacks, the present invention provides a write circuit means for generating a write signal to a magnetic disk drive from input data,
A magnetic disk controller having read circuit means for generating output data from a signal read from the magnetic disk device; a write compensation circuit for varying test write data from the write circuit means; Means for generating data, and, during a test, replacing the test write data with the input data and applying the test write data to the write compensation circuit via the write circuit means to read an output signal of the write compensation circuit from the magnetic disk device. And a coincidence detecting means for checking the coincidence between the output data of the read circuit means and the test write data at the time of a test.

[0008]

At the time of testing, a test write signal is generated, and the test write signal is used as an input to make a round from the write circuit means to the read circuit means via the selector means, and the input signal to the write circuit means and the read circuit means The self-diagnosis can be performed only by the magnetic disk control device side without actually connecting the magnetic disk device by comparing the output signal with the output signal and checking whether or not the two signals match.

[0009]

First, a reference example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a reference example of the present invention. FIG. 2 is a waveform diagram of the MFM recording method.

In FIG. 1, an integrated circuit (disk controller) FDC for writing / reading data to / from a magnetic disk device (not shown) is a selector for switching between read data from the magnetic disk device and test write data output from the mixer 6. 1 and WINDO for separating the clock pulse and the data pulse in the read signal.
A PLL circuit 2 for generating a W signal; a data separator 3 for separating data from a read signal by a WINDOW signal; a serial / parallel conversion circuit 4 for converting the separated data into 8-bit data; Host interface circuit 5 for sending to the bus
A parallel-to-serial conversion circuit 7 for converting the 8-bit data transmitted through the host interface circuit 5 at the time of writing and the test write data at the time of testing into a serial signal, respectively; A mixer 6 for adding a signal to the magnetic disk drive as write data and outputting the write data to the selector 1 as test write data for testing.
An instruction decoder 9 for decoding the read data output from the host interface circuit 5, comparing the read data output with the test write data transmitted by the firmware, and testing whether or not they match, and
It comprises a read-only memory (ROM) 10 containing firmware and a test control circuit 8 for instructing the selector 1 to switch the input by the output of the instruction decoder 9. The data separator 3 and the serial / parallel conversion circuit 4 mainly form read circuit means, and the mixer 6 and the parallel / serial conversion circuit 7 form write circuit means.

The output of the selector 1 is input to the PLL circuit 2 and the data separator 3, and the WIN output from the PLL circuit 2
The DOW signal is input to the data separator 3. The data separator 3 separates clock and data based on the output of the selector 1 and the output of the PLL circuit 2, and outputs data to the serial / parallel conversion circuit 4. The serial / parallel conversion circuit 4 converts the serial data signal of the data separator 3 into 8-bit parallel data, and transfers the data to an external control device via the host interface circuit 5. Conversion of data to be written to the magnetic disk device from the external control device is supplied to the parallel / serial conversion circuit 7 via the host interface circuit 5 and input to the mixer 6 as a serial data signal. The mixer 6 adds a clock signal to the serial data input and outputs it as a write signal to the FFD. The ROM 10 containing the firmware includes a control firmware portion and a test firmware portion. The value set in the test firmware of the ROM 10 is input to the parallel-serial conversion circuit 7 and the instruction decoder 9 as test write data. The output of the instruction decoder 9 is input to the test control circuit 8. The output of the test control circuit 8 switches between two inputs of the selector 1. That is, read data from the magnetic disk drive and test write data from the mixer 6 are switched and input to the selector 1.

In normal operation, the selector 1 is connected to the external F
A read signal from the DD is input to the PLL circuit 2 and the data separator 3.

Next, in the self-diagnosis of FDC, RO
It operates according to the contents of the test firmware and control firmware of M10. Since the selector 1 performs input switching by the instruction decoder 9 and the test control circuit 8 by the test firmware, the FDC processes the write data for test as read data from the magnetic disk device inside the FDC. That is, the write circuit means including the parallel-serial conversion circuit 7 and the mixer 6 fetches data from the external control device and outputs it as write data to the magnetic disk device in the normal operation, but sets it in the test firmware at the time of the test. The value thus set is sent to the selector 1 as test write data. The PLL circuit 2 and the data separator 3 process the output data for test as read data, take in the data via the serial / parallel conversion circuit 4, and output the data to the host interface circuit 5. Further, the output of the host interface circuit 5 is compared with the test write data decoded by the instruction decoder 9 and transmitted by the firmware, and a test is made to see if they match. According to this embodiment, if the test write data output by itself can be received as read data, it can be determined that the write circuit means and read circuit means of the FDC are operating normally. These comparisons and judgments are controlled according to the contents of the control firmware.

FIG. 3 is a block diagram showing the configuration of the embodiment of the present invention.

In the embodiment, in order to suppress the peak shift in the magnetic disk device in the magnetic disk controller of the reference example, in the magnetic disk controller, the position of the pulse is opposite to the peak shift expected by the data pattern. Is provided with a write compensation circuit 16 for shifting. Normally, in a magnetic disk controller, a write signal is output from a magnetic disk controller, so that data without any frequency fluctuation is a read signal from a magnetic disk device . This is because the PLL circuit 2 follows the fluctuating signal and
This is not a sufficient test for the operation of generating the INDOW signal. In the present embodiment, a PLL test can be performed by adding a variation to the write signal to the magnetic disk originally output from the magnetic disk controller by the write compensation circuit 16.

[0016]

According to the self-diagnosis method of the present invention, the test write signal is a read signal from the FDD in the test, so that the read and write circuits of the FDC do not exchange signals with the outside at the same time. In addition to being able to perform a test, the PLL can be tested by adding a variation to a write signal to the magnetic disk originally output from the magnetic disk controller by the write compensation circuit. Also, in a test in an LSI tester, after a signal is supplied so that the FDC starts a self-diagnosis operation, it is only necessary to wait for a diagnostic result of the FDC, so that there is an effect that the test becomes very simple.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a reference example of the present invention.

FIG. 2 is a waveform diagram of an MFM recording method.

FIG. 3 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 4 is a block diagram showing the configuration of a conventional embodiment.

[Explanation of symbols]

 Reference Signs List 1 selector 2 PLL circuit 3 data separator 4 serial / parallel conversion circuit 5 host interface circuit 6 mixer 7 parallel / serial conversion circuit 8 test control circuit 9 instruction decoder 10 ROM 11 selector 12 PLL circuit 13 data separator 14 serial / parallel Conversion circuit 15 Host interface circuit 16 Write compensation circuit 17 Mixer 18 Parallel / serial conversion 19 Test control circuit 20 Instruction decoder 21 ROM 22 PLL circuit 23 Data separator 24 Serial / parallel conversion 25 Host interface circuit 26 Mixer 27 Parallel Serial conversion 28 ROM

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 20/18

Claims (1)

(57) [Claims] 1. A magnetic disk control device comprising: write circuit means for generating a write signal to a magnetic disk device from input data; and read circuit means for generating output data from a signal read from the magnetic disk device. The test write data from the write circuit means
A write compensation circuit for providing a change for the means for generating the test write data, via the write circuit means instead of the test write data during the test on the data the input applied to the write compensation circuit, wherein Selector means for providing an output signal of the write compensation circuit to the read circuit means in place of a signal read from the magnetic disk device, and checking whether the output data of the read circuit means matches the test write data during a test. A self-diagnosis method for a magnetic disk control device, comprising: coincidence detection means.