– 143–
CXD3068Q
• 2N-track jump
When $4C ($4D for REV) is received from the CPU, a FWD (REV) 2N-track jump is performed in
accordance with Fig. 4-9. The track jump count N is set with register 7. Although N can be set to 2
16
tracks,
note that the setting is actually limited by the actuator. COUT is used for counting the number of jumps
when N is less than 16, and MIRR is used with N is 16 or more.
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.
• Fine search
When $44 ($45 for REV) is received from the CPU, a FWD (REV) fine search (N-track jump) is performed
in accordance with Fig. 4-10. The differences from a 2N-track jump are that a higher precision is achieved
by controlling the traverse speed, and a longer distance jump is achieved by controlling the sled. The track
jump count is set with register 7. N can be set to 2
16
tracks. After kicking the actuator and sled, the traverse
speed is controlled based on the overflow G. Set kick D and F with register 6 and overflow G with register 5.
Also, sled speed control during traverse can be turned off by causing COMP to fall. Set the number of
tracks during which COMP falls with register B. After N tracks have been counted through COUT, the brake
is applied to the actuator and sled. (This is performed by turning on the tracking servo for the actuator, and
by kicking the sled in the opposite direction during the time for kick D set with register 6.) Then, the tracking
and sled servos are turned on.
Set overflow G to the speed required to slow up just before the track jump terminates. (The speed should
be such that it will come on-track when the tracking servo turns on at the termination of the track jump.) For
example, set the target track count N –
α
for the traverse monitor counter which is set with register B, and
COMP will be monitored. When the falling edge of this COMP is detected, overflow G can be reset.
• M-track move
When $4E ($4F for REV) is received from the CPU, a FWD (REV) M-track move is performed in
accordance with Fig. 4-11. M can be set to 2
16
tracks. Like the 2N-track jump, COUT is used for counting
the number of moves when M is less than 16, and MIRR is used when M is 16 or more. The M-track move
is executed by moving only the sled, and is therefore suited for moving across several thousand to several
ten-thousand tracks. In addition, the track and sled servos are turned off after M tracks have been counted
through COUT or MIRR unlike for the other jumps. Transfer $25 from the microcomputer after the actuator
has stabilized.
Summary of Contents for PV420S
Page 1: ...SERVICE MANUAL PV420S WWW BBK RU ...
Page 72: ... 69 CXD3068Q Block Diagram ...
Page 73: ... 70 CXD3068Q Pin Configuration ...
Page 122: ... 119 CXD3068Q Timing Chart 1 3 ...
Page 123: ... 120 CXD3068Q Timing Chart 1 4 ...
Page 124: ... 121 CXD3068Q Timing Chart 1 5 ...
Page 129: ... 126 CXD3068Q Timing Chart 2 1 ...
Page 130: ... 127 CXD3068Q Block Diagram 2 2 ...
Page 131: ... 128 CXD3068Q Timing Chart 2 3 ...
Page 134: ... 131 CXD3068Q Timing Chart 2 6 ...
Page 138: ... 135 CXD3068Q VCO C Mode Fig 3 3 Access Flow Chart Using VCO Control ...
Page 140: ... 137 CXD3068Q Block Diagram 4 1 ...
Page 143: ... 140 CXD3068Q Timing Chart 4 4 ...
Page 147: ... 144 CXD3068Q Fig 4 6 a Auto Focus Flow Chart Fig 4 6 b Auto Focus Timing Chart ...
Page 148: ... 145 CXD3068Q Fig 4 7 a 1 Track Jump Flow Chart Fig 4 7 b 1 Track Jump Timing Chart ...
Page 149: ... 146 CXD3068Q Fig 4 8 a 10 Track Jump Flow Chart Fig 4 8 b 10 Track Jump Timing Chart ...
Page 150: ... 147 CXD3068Q Fig 4 9 a 2N Track Jump Flow Chart Fig 4 9 b 2N Track Jump Timing Chart ...
Page 151: ... 148 CXD3068Q Fig 4 10 a Fine Search Flow Chart Fig 4 10 b Fine Search Timing Chart ...
Page 152: ... 149 CXD3068Q Fig 4 11 a M Track Move Flow Chart Fig 4 11 b M Track Move Timing Chart ...
Page 157: ... 154 CXD3068Q Fig 4 15 CD TEXT Data Timing Chart ...
Page 162: ... 159 CXD3068Q Fig 5 3a Fig 5 3b ...
Page 196: ... 193 CXD3068Q Description of Data Readout ...
Page 200: ... 197 CXD3068Q ...
Page 201: ... 198 CXD3068Q ...
Page 202: ... 199 CXD3068Q ...
Page 207: ... 204 CXD3068Q Package Outline Unit mm ...
Page 208: ...This data sheet has been made from recycled paper to help protect the environment 205 ...
