DESCRIPTION OF PIN FUNCTIONS
PIN NO.
39
NAME
Parallel Port
Interrupt
Request 1
SYMBOL
PINTR1
BUFFER
TYPE
O24
DESCRIPTION
This interrupt from the Parallel Port is
enabled/disabled via bit 4 of the Parallel
Port Control Register.
Refer to
configuration registers CR1 and CR3 for
more information.
If EPP or ECP Mode is enabled, this output
is pulsed low, then released to allow sharing
of interrupts.
This active high signal resets the
FDC37C665GT and must be valid for 500
ns minimum. The effect on the internal
registers is described in the appropriate
section. The configuration registers are not
affected by this reset.
In the
FDC37C666GT, the falling edge of reset
latches the jumper configuration.
The
jumper select lines must be valid 50 ns prior
to this edge.
Raw serial bit stream from the disk drive,
low active. Each falling edge represents a
flux transition of the encoded data.
This active low high current driver allows
current to flow through the write head. It
becomes active just prior to writing to the
diskette.
This active low high current driver provides
the encoded data to the disk drive. Each
falling edge causes a flux transition on the
media.
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 ac-
cessed.
OD24
57
Reset
RST
IS
FLOPPY DISK INTERFACE
16
nRead Disk Data nRDATA
IS
10
nWrite
Gate
nWGATE
OD48
9
nWrite
Data
nWDATA
OD48
11
nHead
Select
nHDSEL
OD48
7
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