Sharp FDD-412A - Page 47

. FDD412A/B
(13) FILE DATA-N
0
1
0
J.
1
0
0
FM
method
|
|
|
|
lf
a
|
|
|
||
Ti+
ae
Rs
et
MFM
method
lf
ia
L|
|
=
Ty,
———+=—
Ts
—#
——
Ts
——$
1
T7
Ty
=
2
aBES)
(TYP)
Ty
=
4
us
(TYP)
T2
=
4
us
(TYP)
Ts
= 2
us
(TYP)
T3
=
220
ns
(TYP)
Te
=
3
Us
(TYP)
T7 = 220 ns (TYP)
A
SEPARATED
DATA
signal
is
in
effect
when
the
VFO
is
used.
This
signal
is
unpredictable
when
nothing
is
written,
the
head
is
not
loaded
on,
or
a
seek
operation
is
performed.
Fig. 2.54 FILE DATA-N Signal Timing
(14) INDEX-N
INDEX-N
|
|
il ms + 0.6 ms
+—— 166.7 ms + 3.4% ———4
Index detecting
position
Inter-device difference in value < +] ms
Y
Head
position
Fig. 2.55 INDEX Signal Timing
(15)
SEPARATED
DATA-N
SEPARATED
CLOCK-N
VFO
CLOCK-N
Refer
to
Figs.
2.56
and
2.57
The
VFO
CLOCK
can
be
set
for
type
A
or
B
by
changing
shorting-
plug
locations
on
the
PCB.
The
period
of
time
for
the
VFO
to
start
is
192
us
from
the
beginning
of
the
VFO
area.
It
is
necessary
for
data
to
be
read
in
after
an
elapsed
time
of
192
Us.
—4i-