LC78624E Datasheet, PDF (17/27 Pages) Sanyo Semicon Device – Compact Disc Player DSP

LC78624E
Note: 1. When the desired track count has been input in binary, the track check operation is started by the fall of RWC.
2. During a track check operation the TOFF pin goes high and the tracking loop is turned off. Therefore, feed motor forwarding is required.
3. When a track check in/out command is issued the function of the WRQ signal switches from the normal mode subcode Q standby monitor function
to the track check monitor function. This signal goes high when the track check is half completed, and goes low when the check finishes. The
microcontroller should monitor this signal for a low level to determine when the track check completes.
4. If a two-byte reset command is not issued, the track check operation will repeat. That is, to skip over 20,000 tracks, issue a track check 201
command once, and then count the WRQ signal 100 times. This will check 20,000 tracks.
5. After performing a track check operation, use the brake command to have the pickup lock onto the track.
8. Error Flag Output; Pin 48: EFLG, pin 52: FSX
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The FSX signal is generated by dividing the crystal oscillator clock, and is a 7.35 kHz frame synchronization signal.
The error correction state for each frame is output from EFLG. The FSX low-level period indicates the C1 correction
state, and the high-level period indicates the C2 correction state. The playback OK/NG state can be easily determined
from the extent of the high level that appears here.
9. Subcodes P, Q and R to W Output Circuit; Pin 49: PW, pin 47: SBSY, pin 50: SFSY, pin 51: SBCK
PW is the subcode signal output pin, and all the codes, P, Q, and R to W can be read out by sending eight clocks to
the SBCK pin within 136 µs after the fall of SFSY. The signal that appears on the PW pin changes on the rising edge
of SBCK. SFSY is a signal that is output for each subcode frame cycle, and the falling edge of this signal indicates
standby for the output of the subcode symbol (P to W). Subcode data P is output on the fall of this signal. However,
when the text data is read or reset, subcodes cannot be read because the LC78624E is in the text mode. The subcodes
can be read by inputting the SW1P ON command.
Code
$4E
$4F
Command
SW1P OFF
SW1P ON
RES = low
q
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SBSY is a signal output for each subcode block. This signal goes high for the S0 and S1 synchronization signals. The
fall of this signal indicates the end of the subcode synchronization signals and the start of the data in the subcode
block. (EIAJ format)
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No. 5811-17/27