LC78624E Datasheet, PDF (16/27 Pages) Sanyo Semicon Device – Compact Disc Player DSP

LC78624E
6. Tracking brake
The chart shows the relationships between the TES, HFL, and TOFF signals during the track jump C period. The TOFF signal is extracted from the
HFL signal by TES signal edges. When the HFL signal is high, the pickup is over the mirror surface, and when low, the pickup is over data bits.
Thus braking is applied based on the TOFF signal being high when the pickup is moving from a mirror region to a data region and being low when
the pickup is moving from a data region to a mirror region.
• JP three-value output
A09911
Code
$B6
$B7
Command
JP THREE-VALUE OUTPUT
JP TWO-VALUE OUTPUT (earlier scheme)
RES = low
q
The JP three-value output command allows the track jump operation to be controlled from a single pin.
Two-value
output
Three-value
output
A09912
• Track check mode
Code
$F0
$F8
$FF
Command
TRACK CHECK IN
TRACK CHECK OUT
TWO-BYTE COMMAND RESET
RES = low
q
The LC78624E will count the specified number of tracks plus one when the microcontroller sends an arbitrary
binary value in the range 8 to 254 after issuing either a track check in or a track check out command.
A09913
No. 5811-16/27