W83977F-A Datasheet, PDF (23/182 Pages) Winbond – WINBOND I/O

W83977F-A/ W83977G-A/ W83977AF-A/ W83977AG-A
4.6 FDC Interface
SYMBOL
DRVDEN0
DRVDEN1
GP10
(IRQIN1)
P12
PIN I/O
FUNCTION
2 OD24 Drive Density Select bit 0.
3 OD24 Drive Density Select bit 1.
Alternate Function 1: General purpose I/O port 1, bit 0. It can be configured
as an interrupt channel.
Alternate Function 2: Keyboard P12 I/O port.
DSRC
HEAD
WE
WD
STEP
DIR
MOB
DSA
DSB
MOA
DSKCHG
RDATA
WP
TRAK0
INDEX
Alternate Function 3: DSR input of UART C [W83977AF only]
5 OD24 Head select. This open drain output determines which disk drive head is
active.
Logic 1 = side 0; Logic 0 = side 1
9 OD24 Write enable. An open drain output.
10 OD24 Write data. This logic low open drain writes precompensation serial data to
the selected FDD. An open drain output.
11 OD24 Step output pulses. This active low open drain output produces a pulse to
move the head to another track.
12 OD24 Direction of the head step motor. An open drain output.
Logic 1 = outward motion; Logic 0 = inward motion
13 OD24 Motor B On. When set to 0, this pin enables disk drive 1. This is an open
drain output.
14 OD24 Drive Select A. When set to 0, this pin enables disk drive A. This is an open
drain output.
15 OD24 Drive Select B. When set to 0, this pin enables disk drive B. This is an open
drain output.
16 OD24 Motor A On. When set to 0, this pin enables disk drive 0. This is an open
drain output.
4
INcs Diskette change. This signal is active low at power on and when the diskette
is removed. This input pin is pulled up internally by a 1 K　resistor, which can
can be disabled by bit 7 of L0-CRF0 (FIPURDWN).
6
INcs The read data input signal from the FDD. This input pin is pulled up internally
by a 1 K　 resistor, which can be disabled by bit 7 of L0-CRF0 (FIPURDWN).
7
INcs 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　 resistor, which can be disabled by bit 7 of L0-CRF0 (FIPURDWN).
8
INcs 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　 resistor, which can be disabled by bit 7 of L0-CRF0
(FIPURDWN).
17 INcs 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, which can be disabled by bit 7 of
L0-CRF0 (FIPURDWN).
Publication Release Date: May 2006
-15 -
Revision 0.60