W83787IF Datasheet, PDF (18/123 Pages) Winbond – WINBOND I/O WITH SERIAL-INFRARED SUPPORT

W83787IF
IDE and FDC Interface, continued
SYMBOL PIN I/O
FUNCTION
STEP
82 OD Step output pulses. This active low open drain output produces a
pulse to move the head to another track.
INDEX
81
I This schmitt input from the disk drive is active low when the head is
positioned over the beginning of a track marked by an index hole.
This input pin is pulled up internally by an approximately 1K ohm
resistor. The resistor can be disabled by bit 4 of CR6 (FIPURDWN).
TRAK0
78
I Track 0. This schmitt input from the disk drive is active low when the
head is positioned over the outermost track. This input pin is pulled
up internally by an approximately 1K ohm resistor. The resistor can
be disabled by bit 4 of CR6 (FIPURDWN).
WP
77
I Write protected. This active low schmitt input from the disk drive
indicates that the diskette is write-protected. This input pin is pulled
up internally by an approximately 1K ohm resistor. The resistor can
be disabled by bit 4 of CR6 (FIPURDWN).
RDATA
74
I The read data input signal from the FDD. This input pin is pulled up
internally by an approximately 1K ohm resistor. The resistor can be
disabled by bit 4 of CR6 (FIPURDWN).
DSKCHG
76
I Diskette change. This signal is active low at power on and whenever
the diskette is removed. This input pin is pulled up internally by an
approximately 1K ohm resistor. The resistor can be disabled by bit 4
of CR6 (FIPURDWN).
MOA
79 OD Motor A On. When set to 0, this pin enables disk drive 0. This is an
open drain output.
MOB
80 OD Motor B On. When set to 0, this pin enables disk drive 1. This is an
open drain output.
DSA
83 OD Drive Select A. When set to 0, this pin enables disk drive A. This is
an open drain output.
DSB
84 OD Drive Select B. When set to 0, this pin enables disk drive B. This is
an open drain output.
VDD
15, 56
+5 power supply for the digital circuitry
GND
25, 40
65, 90
Ground
Table 1-1:
PARALLEL PORT FUNCTION MODE
POWER-ON SETTING
PDRQX
HPRTM1
L
L
H
H
GMWR
HPRTM0
L
H
L
H
Printer Mode (Default)
ECP/EPP
EPP
EXT2FDD
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Publication Release Date:Sep 1995
Revision A1