LC78621E Datasheet, PDF (26/34 Pages) Sanyo Semicon Device – Compact Disc Player DSP

LC78621E
• The ASDACK (pin 38), ASDFIN (pin 39), ASDFIR (pin 40), and ASLRCK (pin 41) pins must be held low if this
mode is not used.
MSB
LSB
01101100
01101011
01101111
01101110
Command
ANTIC ON
ANTIC OFF
DF NORMAL SPEED ON (only in antishock mode)
DF NORMAL SPEED OFF (only in antishock mode)
RES = low
q
q
• It is possible to input the signals from the ROMXA (pin 44), C2F (pin 45), LRSY (pin 42), and CK2 (pin 43) pins
to an antishock LSI (the Sanyo LC89151) and re-input the signals output by the antishock LSI to the ASDFIN (pin
39), ASLRCK (pin 41), and ASDACK (pin 38) pins. These signals are then processed by the attenuator, 8×
oversampling digital filter, and one-bit D/A converter circuits and output as audio signals.
• In antishock systems, the signal-processing block must operate in double-speed playback mode for data output to
the antishock LSI, and the audio playback block (the attenuator, 8× oversampling digital filter, and one-bit D/A
converter circuits) must operate at normal speed. This means that the control microprocessor must issue both the
ANTIC on command (6CH) as well as the DF normal speed on command (6FH).
• The ANTIC off command (6BH) clears antishock mode.
23. CONT Pin; Pin 73: CONT
MSB
LSB
00001110
10001011
Command
CONT SET
CONT AND CD-ROM XA RESET
The CONT pin goes high when a CONT SET command is issued.
24. Clock Oscillator; Pin 77: X_IN, pin 78: X_OUT
MSB
LSB
10001110
10001101
11000010
11000001
Command
OSC ON
OSC OFF
NORMAL-SPEED PLAYBACK
DOUBLE-SPEED PLAYBACK
The clock that is used as the time base is generated by connecting a 16.9344
MHz oscillator element between these pins. The OSC OFF command turns off
both the VCO and crystal oscillators. Double-speed playback can be specified
by microprocessor command.
RES = low
Low
q
RES = low
q
q
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