CXD3018Q/R
$47 latch
XLAT
FOK
(FZC)
BUSY
Command for
DSSP
Blind E
$08
$03
Fig. 4-6-(b). Auto Focus Timing Chart
(b) Track jump
1, 10 and 2N-track jumps are performed respectively. Always use this when the focus, tracking, and sled
servos are on. Note that tracking gain-up and braking-on should be sent beforehand because they are not
involved in this sequence.
• 1-track jump
When $48 ($49 for REV) is received from the CPU, a FWD (REV) 1-track jump is performed in accordance
with Fig. 4-7. Set blind A and brake B with register 5.
• 10-track jump
When $4A ($4B for REV) is received from the CPU, a FWD (REV) 10-track jump is performed in accordance
with Fig. 4-8. The principal difference from the 1-track jump is to kick the sled. In addition, after kicking the
actuator, when 5 tracks have been counted through COUT, the brake is applied to the actuator. Then, when
the actuator speed is found to have slowed up enough (determined by the COUT cycle becoming longer than
the overflow C set with register 5), the tracking and sled servos are turned on.
• 2N-track jump
When $4C ($4D for REV) is received from the CPU, a FWD (REV) 2N-track jump is performed in accordance
16
with Fig. 4-9. The track jump count N is set with register 7. Although N can be set to 2 tracks, note that the
setting is actually limited by the actuator. COUT is used for counting the number of jumps.
Although the 2N-track jump basically follows the same sequence as the 10-track jump, the one difference is
that after the tracking servo is turned on, the sled continues to move only for "D", set with register 6.
• N-track move
When $4E ($4F for REV) is received from the CPU, a FWD (REV) N-track move is performed in accordance
16
with Fig. 4-10. N can be set to 2 tracks. COUT is used for counting the number of jumps. The N-track move
is executed only by moving the sled, and is therefore suited for moving across several thousand to several
ten-thousand tracks.
– 71 –
ETC [ ETC ]
