STV8203 ST Microelectronics, STV8203 Datasheet - Page 7

• Manufacturer Part Number: STV8203
• Description: MULTISTANDARD TV SOUND DEMODULATOR
• Manufacturer: ST Microelectronics

USING STV8203
1 - Hardware
1.a - Power Supplies (see Figure 2)
The IC is using two main power supplies :
- DV
- AV
Figure 2
1.b - Sound Subcarrier Filters
Sound demodulation and decoding are very easy
with thisdevice providing all the necessaryfunctions
for that purpose, including the channel filters.
TheseFIR base-bandfilters give the best selectivity
of the desired channeland providesin NICAM mode
the correct cosine roll-off response.
This implies that no external filters are required
(except may be a simple high-pass filter, if the saw
filters and sound IF demodulators used in the ap-
plication create picture interferences).
The filters can be automatically set for B/G/H/I/L/L’
standards. They can also be easily tuned through
I
1.c - Audio Matrix
The mono output (MOUT) can output L1, R1 or
(L1+R1)/2 signal. A typical application is the possi-
bility to record a selected channel in mono mode on
the lineartrack of a VCR separatelyfrom the record-
ing ofthe stereo signal,providingthe facility to select
2
This power supply can be switched-off in stand-
by mode.
then the output voltage swing on output pins can
reach 2V
swing on output pins can reach 1V
C for M, D, K, K1.
CC
DD5
Pins 5-32-42
supplies the audio matrixpart : if V
supplies all the digital part V
AND CONTROL PART
RMS
DEMODULATION
GND
, if V
DV
Nom.
41
DD5
= 5V then the output voltage
MATRIX
AUDIO
AV
21
11
RMS
CC
GND
Nom.
.
Nom.
= 5V.
= 8V
between stereo or mono signals in the playback
mode in case of marginal noise conditions.
1.d - Stand-by
Stand-by with THRU mode : the analog part of the
device has its own power supply (AV
this part to keep working even when the digital part,
powered by the 5V power supply (DV
stand-by.
In this case, the audio matrix is put in a special
setting :
- LIL1 to AOL2,
- LIR1 to AOR2,
- LIL2 to AOL1,
- LIR2 to AOR1,
- input gain = 0dB.
This allows to achieve a ”THRU” mode from
SCART1 input to SCART2 output and SCART2
input to SCART1 output, providing a copy facility
from SCARTIN to SCARTOUT.
2 - Software
Two modes of operation are available :
2.a - Optimized Program Mode
Four standards have default setting stored in order
to allow a very easy programmation. Only some
registers may have to be programmed (these reg-
isters are shown in bold in the Figure 3) but in most
cases, the reset values will be sufficient. In Fig-
ure 3, CTL and STAT represent registers which are
controlled by the ”standard processor”. These reg-
isters are located between address 23Hex and
3CHex in the complete list of registers.
2.b - Advanced Operation Mode
In that mode, all the read/write registers (as men-
tionned in the complete list) can be programmed
manually and changed from their reset values.
The additionnal registers accessible in this mode
are shown in bold in Figure 4. This mode can be
selected by putting the bits [3:0] of AO-CONTROL
register to 0.
CC
STV8203
DD5
) allowing
), is in
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