LC78622NE Datasheet, PDF (20/31 Pages) Sanyo Semicon Device – Compact Disc Player DSP

LC78622NE
ATT DATA
Audio output level = 20 log _100H [dB]
For example, the formula below calculates the time required for the attenuation level to increase from 00H to EEH
when a 4STEP UP command is executed. Note that the control microprocessor must provide enough of a time
margin for this operation to complete before issuing the next attenuation level set command.
238 level × 4STEP UP
44.1 kHz
≈ 21.6 ms
Note: Setting the attenuation level to values of EFH or higher is disallowed to prevent overflows in one-bit D/A
converter calculations from causing noise.
14. Mute Output; Pin 35: MUTEL/CONT7, pin 42: MUTER/CONT8
15. C2 Flag Output; Pin 30: C2F
C2F output flag information in 8-bit units.
16. Digital Output Circuit; Pin 31: DOUT
This is an output pin for use with a digital audio interface. Data is output in the EIAJ format. This signal has been
processed by the interpolation and muting circuits. This pin has a built-in driver circuit and can directly drive a
transformer.
MSB
LSB
01000010
01000011
01000000
01000001
10001000
10001011
Command
DOUT ON
DOUT OFF
UBIT ON
UBIT OFF
CDROM-XA
ROMXA-RST
RES = low
q
q
q
• The DOUT pin can be locked at the low level by issuing a DOUT OFF command.
• The UBIT information in the DOUT data can be locked at zero by issuing a UBIT OFF command.
• The DOUT data can be switched to data for which interpolation and muting processing have not been performed
by issuing a CD-ROM XA command.
• When searching and when returning the pickup to its initial position, there are cases when the frequency output
data will contain a parity error and locking is lost temporarily. To prevent this, we recommend directly executing a
UBIT OFF ($41) command and then directly executing a UBIT ON ($40) command when searching and when
returning the pickup to its initial position.
17. Mute Control Circuit
MSB
LSB
00000001
00000011
Command
MUTE: 0 dB
MUTE: –∞ dB
RES = low
q
Inputting the above command mutes the audio level (MUTE -∞ dB). Since zero-cross muting is used, there is very
little noise associated with this operation. The IC defines zero cross to be the ranges where the upper 7 bits of the
data are all zeros or all ones. Note that the MUTE -12 dB instruction supported by the LC78620E has been removed
from this product.
No. 6015-20/31