JPH0381228B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a floppy disk drive (FDD) in which a write/read circuit for a floppy disk drive (FDD) and a control circuit for other systems of the FDD are incorporated into one semiconductor integrated circuit. The present invention relates to a semiconductor integrated circuit device for use in other applications.

[Prior art]

Conventional circuits of this type do not have the functions necessary for FDD.
It was composed of LSTTL, TTL, and discrete elements.

However, in such conventional circuits,
Because products use many LSTTL, TTL, and discrete elements, the number of external parts increases, leading to increased costs, increased man-hours, the inability to reduce size and weight, the inability to save labor, and large variations in equipment, etc. There were some shortcomings.

[Summary of the invention]

The present invention was made in order to eliminate the drawbacks of the above-mentioned prior art, and incorporates a recording circuit and a reading circuit, which are the main functions of FDD equipment, and a logic control circuit for controlling other systems necessary for the above-mentioned equipment. By incorporating it into a semiconductor integrated circuit and arranging a center-tap output power terminal across the high-voltage power supply terminal, it can be made smaller and lighter.
In addition to reducing man-hours and costs,
It is an object of the present invention to provide a semiconductor integrated circuit device for an FDD that can reduce device variations and also reduce the influence of stray capacitance on board wiring.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The drawings show one embodiment of the present invention.
In the figure, 100 is a reading circuit section (READ) for reading the contents recorded on the disk.
CIRCUIT), and this reading circuit section 100
are pulse generators 101, 104, D flip-flop 102, one-shot multivibrator 103, comparator 105, differentiation circuit 106,
Read amplifier 107 and matrix circuit 10
8. Also, this reading circuit 1
00 is an external terminal for connecting one shot external components (ONE SHOT COMPONENTS).
2, 3, 4, 5, External component connection terminals for differentiation circuit (DIFFERENTIATOR COMPONENTS) 6,
7. Differentiator circuit input terminal (ACTIVE
DIFFERENTIATOR INPUT) 8, 9, lead amplifier output terminal (AMPLIFIER OUTPUT) 1
0 and 11, read amplifier gain adjustment terminals (OFFSET DECOUPLING) 12 and 13, and head 1 terminals (HEAD1) 14 and 15. Note that terminal 1 is a non-connection terminal (NC).

Further, 200 is a write/erase circuit section (recording circuit) for erasing information on the front surface of the disk before recording data on the disk, and for recording a signal according to the input on the disk. The erase circuit section 200 includes a write amplifier 20
1. Flip-flop FF-1, write current setting circuit 202, common driver 203, 5V detection circuit 204, erase circuit 205, one-shot multivibrator O/S-1, O/S-2, gate
G30, G31, G33, and matrix circuit 108
It is made up of. The write/erase circuit 200 has external terminals such as head 0 terminals (HEAD 0) 16 and 17, and a common driver terminal (center tap) for selectively selecting two heads and switching between reading and writing. Output power supply terminals) (CT0, CT1) 18, 20, high voltage system power supply voltage terminal (VBB) 19 for supplying high voltage system (12V) power supply voltage to the magnetic head, earth terminals (GND) 21 to 25, erasing circuit Output terminal (ERASE) 26, write current setting terminal (CURRENT ADJ) 27, and external component connection terminal for one shot (ONE SHOT-1, -2) 2
8,29.

300 is a control circuit unit for controlling the system necessary for the FDD device, and this control circuit unit 30
0 is one-shot multivibrator O/S-
3~O/S-5, flip-flop FF-2,-
3, and each gate. Further, in this control circuit section 300, 31, 32, 34
are one-shot multivibrator O/
External component connection terminals for time constant setting of S-3, -4, -5 (ONE SHOT-3, -4, -5), 33 is 5V
-Vc.c. terminal, 35 is a reset terminal ( ) when the power is turned on, 36 is a voltage control output terminal ( ), 37 to 40 are stepper drive output terminals (STEPPER
41 is a track 0 sensor terminal (TRACK 0 SENSOR) for checking whether the head is at track 0 position, 42 is an FPT sensor terminal (FPT SENSOR) for detecting whether recording to the disk is possible. , 43 is an index sensor terminal (INDEX SENSOR) for checking the rotation status of the disk, 44 is an in-use output terminal ( ), 45 is a non-connection terminal, and 46 is an output status signal indicating whether the disk is rotating normally. 47 is a drive select terminal ( ) for selecting the floppy disk drive unit, 48 is a direction terminal ( ) for setting the direction of movement of the head in and out, and 49 is a drive select terminal ( ) for selecting the floppy disk drive unit. 50 is a step terminal () for moving the track, and a write data terminal (50) for writing data.
DATA), 51 to 55 are ground terminals (GND), 5
6 is a write gate terminal ( ) for selecting read or write, 57 is track 0
The track 0 terminal (0) is used to output a signal when the recording operation is completed.
PROTECT), 59 is a read data terminal ( ) for outputting a reading output of the recorded contents of the disk, and 60 is a side 1 terminal (1) for selecting 0 and 1 of the disk.

The control circuit section 300 includes a control input circuit section having terminals for the drive select, direction, step, write data, write gate, side 1, index sensor, FPT sensor, and track 0 sensor;
It is divided into an output circuit section having write protect, track 0, and read data terminals.
Note that in the figure, the * mark indicates that the output terminal is an open collector.

In this way, according to this embodiment, the logic circuit that controls the system necessary for the FDD device, including the read and write circuits, is incorporated into one semiconductor integrated circuit, so external components and product board area are reduced. Therefore, the number of man-hours and costs can be reduced.
At the same time, it can be made smaller, lighter, and more labor-saving, resulting in a significant reduction in the cost of the product. Furthermore, variations in device products can be suppressed and reliability can be improved.

In addition, we installed a center-tap output power terminal across the high-voltage power supply voltage terminal.
The effect is that there is no need to worry about power supply wiring being formed so as to straddle each other on the printed circuit board on which this integrated circuit device is mounted, external wiring is organized, and the effects of stray capacitance, etc. on the board wiring can be reduced. There is.

〔Effect of the invention〕

As described above, according to the present invention, a recording circuit and a reading circuit, which are the main devices of an FDD device, and a control circuit for controlling a system necessary for the device are incorporated into one semiconductor integrated circuit. In addition, the center-tapped output power terminal is arranged across the high-voltage power supply terminal, making it possible to reduce the size and weight, reduce man-hours, reduce costs, reduce device variations, and reduce board wiring. This has the effect of reducing the influence of stray capacitance, etc.

[Brief explanation of drawings]

The drawing is a configuration diagram of a semiconductor integrated circuit device for FDD according to an embodiment of the present invention. 100...reading circuit section, 200...writing/
Erasing circuit section (recording circuit), 300...control circuit section,
18, 20...Common driver terminal (center tap output power supply terminal), 19...High voltage system power supply voltage terminal.

Claims (1)

[Scope of Claims] 1. A semiconductor integrated circuit device for a floppy disk drive, comprising: a recording circuit for recording a signal according to an input on a floppy disk; and a reading circuit for reading contents recorded on the floppy disk. A high-voltage power supply terminal is formed by incorporating the circuit and a control circuit for controlling the system necessary for floppy disk drive equipment into the same semiconductor integrated circuit, and supplies high-voltage power supply voltage to the magnetic head. A semiconductor for a floppy disk drive, characterized in that two center tap output power terminals are arranged between the two heads for selectively selecting two heads and switching between reading and writing. Integrated circuit device.