CXA1782CQ/CR
Note that the time from the High to Low transition of FZC to the time command $08 is asserted must be
minimized. To do this, the software sequence shown in B is better than the sequence shown in A.
Transfer $08
FZC ↓ ?
YES
NO
NO
F. OK ?
YES
F. OK ?
YES
NO
NO
Transfer $08
FZC ↓ ?
YES
Latch
(A)
Latch
(B)
Fig. 5. Poor and good software command sequences
1-3. SENS pin (Pin 24)
The output of the SENS pin differs depending on the input data as shown below.
$0X: FZC
$1X: DEFECT
$2X: TZC
$3X: Automatic adjustment comparator output
$4X to 7X: HIGH-Z
2. $1X (“DEFECT” at SENS pin (Pin 24))
These commands deal with switching TG1/TG2, brake circuit ON/OFF, and the sled kick output.
The bit configuration is as follows
Sled kick height
Relative
value
D7
0
D6
0
D5
0
D4
1
D3
D2
D1
D0
D1
(PS1)
D0
(PS0)
TG1, TG2 Break
circuit
Sled kick
height
±1
±2
0
0
0
1
ON/OFF
ON/OFF
±3
±4
1
1
0
1
TG1, TG2
The purpose of these switches is to switch the tracking servo gain Up/Normal. TG1 and TG2 are interlinked
switches. The brake circuit (TM7) is to prevent the occurrence of such frequently occurring phenomena as
extremely degraded actuator settling due to the servo motor exceeding the linear range causing what should
be a 100-track jump to fall back down to a 10-track jump after a 100 or 10-track jump has been performed. To
do this, when the actuator travels radially; that is, when it traverses from the inner track to the outer track of
the disc and vice versa, the brake circuit utilizes the fact that the phase relationship between the RF envelope
and the tracking error is 180˚out-of-phase to cut the unneeded portion of the tracking error and apply braking.
– 24 –
ETC [ ETC ]
