W83977EG Datasheet, PDF (19/142 Pages) Winbond – WINBOND ISA I/O

W83977EF-AW/W83977EG-AW
4.6 FDC Interface
SYMBOL
DRVDEN0
DRVDEN1
GP10
(IRQIN1)
P12
SCI#
HEAD#
WE#
WD#
STEP#
DIR#
MOB#
DSA#
DSB#
MOA#
DSKCHG#
RDATA#
WP#
TRAK0#
INDEX#
PIN
I/O
FUNCTION
2
OD₂₄ Drive Density Select bit 0.
3
OD₂₄ Drive Density Select bit 1. (CR2A bit 1_0 = 00, default)
IO_24t General purpose I/O port 1 bit 0. (CR2A bit 1_0 = 01)
Alternate Function from GP10: Interrupt channel input.
IO_24t KBC P12 I/O port. (CR2A bit 1_0 = 10)
OUT_12t System Control Interrupt (CR2A bit 1_0 = 11)
Head select. This open drain output determines which disk drive
5
OD₂₄
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 pre-compensation
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.
Direction of the head step motor. An open drain output.
12
OD₂₄ 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.
Diskette change. This signal is active low at power on and
4
IN_cs
whenever the diskette is removed. This input pin is pulled up
internally by a 1 KΩ resistor. The resistor can be disabled by bit 7
of L0-CRF0 (FIPURDWN).
The read data input signal from the FDD. This input pin is pulled
6
IN_cs up internally by a 1 KΩ resistor. The resistor can be disabled by
bit 7 of L0-CRF0 (FIPURDWN).
Write protected. This active low Schmitt input from the disk drive
7
IN_cs
indicates that the diskette is write-protected. This input pin is
pulled up internally by a 1 KΩ resistor. The resistor can be
disabled by bit 7 of L0-CRF0 (FIPURDWN).
Track 0. This Schmitt-triggered input from the disk drive is active
8
IN_cs
low when the head is positioned over the outermost track. This
input pin is pulled up internally by a 1 KΩ resistor. The resistor
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
17
IN_cs by an index hole. This input pin is pulled up internally by a 1 KΩ
resistor. The resistor can be disabled by bit 7 of L0-CRF0
(FIPURDWN).
Publication Release Date: Apr. 2006
-17-
Revision 1.2