LC78626E Datasheet, PDF (23/32 Pages) Sanyo Semicon Device – DSP for Compact Disk Players

LC78626E
44.1 kHz (normal speed), 88.2 kHz (double speed)
Start
Stop
ATT DATA
The audio output level = 20 log ————— [dB]
100H
Because, for example, the time that it would take to increase the attenuation level from “00H” to “EEH” using the 4
step-up command would be as calculated below, this amount of time must be left before entering the next attenuation
level command:
238 level × 4 Step-up
————————— ≈ 21.6 ms (approx.)
44.1 kHz (LRSY)
* In order to prevent noise due to arithmetic overflow in the one-bit D/A converter, settings greater than EEH are
prohibited.
14 The Mute Output Pin 51: MUTEL, Pin 57: MUTER
When the Mute control (MUTE –∞ dB: $03) is exerted, and once the data for each channel has been continuously at
“0” for a specified amount of time, then this output goes high. Afterwards, when data is again entered, this output
immediately goes low.
15 The C2 Flag Output Pin 46: C2F
C2F is an 8-bit unit flag that indicates the data error status.
16 The Digital OUT Output Circuit Pin 39: DOUT
This is the digital audio interface output pin. Its output is in EIAJ format. This signal is interpolated, and the signal is
output through the MUTE circuit. Because this output pin is equipped with an internal driver, it can drive a
transformer directly.
Code
$42
$43
$40
$41
$88
$8B
COMMAND
DOUT ON
DOUT OFF
UBIT ON
UBIT OFF
CDROM-XA
ROMXA-RST
RES = low
q
q
q
* The digital OUT pin can be fixed low by inputting the DOUT OFF command.
* Of the DOUT data, the UBIT data can be fixed at low by entering the UBIT OFF command.
* By entering the CDROM-XA command, the DOUT pin can be switched to CD-ROM data that is not subjected to
interpolation or to mute control. (When this is done, the audio output is put into mute mode.) The ROMXA-RST
command returns the DOUT pin to the audio data output mode which is subject to interpolation and mute control.
(When this is done, the audio output mute is released.)
17 The Mute Control Circuit
Code
$01
$03
COMMAND
MUTE 0 dB
MUTE –∞ dB
RES = low
q
The sound level can be muted (MUTE –∞ dB) by the entry of the commands above. Because zero cross mute is used,
there is little noise during this operation. The zero cross determination is made in the range where the most significant
7 bits are all “1” or all “0.” Because the MUTE–12 dB command ($02) that was found in the LC78620E and 78621E
has been deleted, the digital attenuator is used and ATT DATA = 60 ($3C) is set.
No. 5692-23/32