LC78681E Datasheet, PDF (18/23 Pages) Sanyo Semicon Device – Digital Signal Processor for Compact Disc Players

LC78681E
Mute Control Circuit
MSB
LSB
00000001
00000010
00000011
Command
Mute 0 dB
Mute –12 dB
Mute ∞ dB
RES = low
Volume can be reduced by 12 dB (MUTE –12 dB) or muted fully (MUTE ∞ dB) by issuing the commands shown above.
Muting switches at zero crossings to prevent switching noise on the audio output. A zero crossing is judged to be any
data where the upper seven bits are all 1 or all 0.
Bilingual Function
MSB
LSB
00101000
00101001
00101010
Command
STO CONT
Lch CONT
Rch CONT
RES = low
• The left and right channels are output to the left and right channels when reset or when the Stereo command (28H) is
issued.
• Left channel data is output to both the left and right channels when the Left Channel Set command (29H) is issued.
• Right channel data is output to both the left and right channels when the Right Channel Set command (2AH) is
issued.
Deemphasis Control (pin 29: EMPH)
The preemphasis on/off bit in the Q subcode data is output on EMPH. Deemphasis is required when EMPH is high.
D/A Converter Interface (pin 31: WCLK, pin 33: LRCLK, pin 35: DFOUT and pin 36: DACLK)
D/A converter data is output in MSB-first format from DFOUT, in synchronization with the falling edge of DACLK.
MSB
LSB
10001000
10001011
Command
CD-ROM XA
CONT and CD-ROM XA Reset
RES = low
Issuing the CD-ROM XA command causes data which does not undergo interpolation or muting control to be output on
DFOUT (when CD-ROM XA is supported). Because the Reset command for CD-ROM XA is common with the CONT
reset on pin 60, caution is required.
• LC78681 D/A Converter Interface
No. 4521-18/23