w83977atg Winbond Electronics Corp America, w83977atg Datasheet - Page 24

• Manufacturer Part Number: w83977atg
• Description: W83877tf Plus Kbc, Gp I/o, Wake-up, Fir, Cir, Pb-free
• Manufacturer: Winbond Electronics Corp America

FDC Interface, continued
DIR
MOB
DSA
DSB
MOA
DSKCHG
RDATA
INDEX
STEP
WP
TRAK0
SYMBOL
PIN
17
11
12
13
14
15
16
4
6
7
8
OD
OD
OD
OD
OD
OD
INcs
IN
IN
IN
IN
I/O
cs
cs
cs
cs
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24
24
24
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Step output pulses. This active low open drain output produces a pulse
to move the head to another track.
Direction of the head step motor. An open drain output.
Logic 1 = outward motion
Logic 0 = inward motion
Motor B On. When set to 0, this pin enables disk drive 1. This is an
open drain output.
Drive Select A. When set to 0, this pin enables disk drive A. This is an
open drain output.
Drive Select B. When set to 0, this pin enables disk drive B. This is an
open drain output.
Motor A On. When set to 0, this pin enables disk drive 0. This is an
open drain output.
Diskette change. This signal is active low at power on and whenever the
diskette is removed. This input pin is pulled up internally by a 1
K  r esistor. The resistor can be disabled by bit 7 of L0
(FIPURDWN).
The read data input signal from the FDD. This input pin is pulled up
internally by a 1 K
CRF0 (FIPURDWN).
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 a 1 K
disabled by bit 7 of L0-CRF0 (FIPURDWN).
Track 0. This Schmitt-triggered 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 a 1 K
can be disabled by bit 7 of L0-CRF0 (FIPURDWN).
This Schmitt-triggered 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 a 1 K
resistor. The resistor can be disabled by bit 7 of L0-CRF0
(FIPURDWN).
- 16 -
resistor. The resistor can be disabled by bit 7 of L0
W83977ATF/W83977ATG
FUNCTION
resistor. The resistor can be
resistor. The resis
-CRF0
tor
-