W83977ATF Datasheet, PDF (17/207 Pages) Winbond – WINBOND I/O

W83977ATF
PRELIMINARY
1.6 FDC Interface
SYMBOL PIN
DRVDEN0
2
DRVDEN1
3
GP10
(IRQIN1)
P12
SCI
HEAD
5
WE
9
WD
10
STEP
11
DIR
12
MOB
13
DSA
14
DSB
15
MOA
16
DSKCHG
4
I/O
OD₂₄
OD₂₄
IO_24t
IO_24t
OD₁₂
OD₂₄
OD₂₄
OD₂₄
OD₂₄
OD₂₄
OD₂₄
OD₂₄
OD₂₄
OD₂₄
IN_cs
FUNCTION
Drive Density Select bit 0.
Drive Density Select bit 1. (CR2A bit 1_0 = 00, default)
General purpose I/O port 1 bit 0. (CR2A bit 1_0 = 01)
Alternate Function from GP10: Interrupt channel input.
KBC P12 I/O port. (CR2A bit 1_0 = 10)
System Control Interrupt. (CR2A bit 1_0 = 11)
In the ACPI power management mode, SCI is driven low by the
power management events.
Head select. This open drain output determines which disk drive
head is active.
Logic 1 = side 0
Logic 0 = side 1
Write enable. An open drain output.
Write data. This logic low open drain writes pre-compensation
serial data to the selected FDD. An open drain output.
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 KΩ resistor. The resistor can be disabled by bit
7 of L0-CRF0 (FIPURDWN).
Publication Release Date: April 1998
-16-
Revision 0.52