SMSC DS – LPC47M192
Page 13
Rev. 03/30/05
DATASHEET
QFP PIN#
NAME
DESCRIPTION
BUFFER
NAME
O12
PWR
WELL
VCC
NOTES
10
nWDATA
Write Disk Data Output. This active low high
current driver provides the encoded data to
the disk drive. Each falling edge causes a
flux transition on the media. Can be
configured as an Open-Drain Output.
Head Select Output. This high current
output selects the floppy disk side for reading
or writing. A logic “1” on this pin means side
0 will be accessed, while a logic “0” means
side 1 will be accessed. Can be configured
as an Open-Drain Output.
Step Direction Output. This high current low
active output determines the direction of the
head movement. A logic “1” on this pin
means outward motion, while a logic “0”
means inward motion. Can be configured as
an Open-Drain Output.
Step Pulse Output. This active low high
current driver issues a low pulse for each
track-to-track movement of the head. Can
be configured as an Open-Drain Output.
This input senses that the drive door is open
or that the diskette has possibly been
changed since the last drive selection. This
input is inverted and read via bit 7 of I/O
address 3F7H. The nDSKCHG bit also
depends upon the state of the Force Disk
Change bits in the Force Disk Change
register (see Runtime Registers section).
Drive Select 0 Output. Can be configured as
an Open-Drain Output.
Motor On 0 Output. Can be configured as
an Open-Drain Output.
This active low Schmitt Trigger input senses
from the disk drive that a disk is write
protected. Any write command is ignored.
The nWRPRT bit also depends upon the
state of the Force Write Protect bit in the
FDD Option register (see the Configuration
Registers section).
This active low Schmitt Trigger input senses
from the disk drive that the head is
positioned over the outermost track.
This active low Schmitt Trigger input senses
from the disk drive that the head is
positioned over the beginning of a track, as
marked by an index hole.
General Purpose I/O
Drive Density Select 0 Output. Indicates the
drive and media selected.
Both functions can be configured as Open-
Drain Output.
General Purpose I/O
Drive Density Select 1 Output. Indicates the
drive and media selected.
Both functions can be configured as Open-
Drain Output.
12
nHDSEL
O12
VCC
8
nDIR
O12
VCC
9
nSTEP
O12
VCC
4
nDSKCHG
IS
VCC
5
nDS0
O12
VCC
3
nMTR0
O12
VCC
15
nWRTPRT
IS
VCC
14
nTRK0
IS
VCC
13
nINDEX
IS
VCC
1
GP40/
DRVDEN0
IO12
VCC
2
GP41/
DRVDEN1
IO12
VCC
5