DESCRIPTION OF PIN FUNCTIONS
QFP/
TQFP
PIN NO.
7
NAME
Direction
Control
SYMBOL
nDIR
BUFFER
TYPE
OD48
DESCRIPTION
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.
This active low high current driver issues a
low pulse for each track-to-track movement
of the head.
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.
Active low open drain outputs select drives
0-1.
These active low open drain outputs select
motor drives 0-1.
Indicates the drive and media selected.
Refer to configuration registers CR03,
CR0B, CR1F.
This active low Schmitt Trigger input senses
from the disk drive that a disk is write
protected. Any write command is ignored.
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.
Indicates the drive and media selected.
Refer to configuration registers CR03,
CR0B, CR1F.
Receiver serial data input for port 2. IR
Receive Data
8
nStep Pulse
nSTEP
OD48
17
Disk Change
nDSKCHG
IS
4,3
2,5
1
nDrive Select
O,1
nMotor On 0,1
DRVDEN0
nDS0,1
nMTR0,1
DRVDEN0
OD48
OD48
OD48
14
nWrite
Protected
nWRTPRT
IS
13
wTrack 00
nTRK00
IS
12
nIndex
nINDEX
IS
18
DRVDEN1
DRVDEN 1
OD48
SERIAL PORT INTERFACE
88
Receive Data 2
RXD2/IRRX
I
8
SMSC [ SMSC CORPORATION ]
