PRELIMINARY DATA SHEET
MSP 34x1G
2.2.3. Preprocessing of Demodulator Signals
– “Stereo or A” channel: Analog or digital mono
sound, stereo if available. In case of bilingual broad-
cast, it contains language A (on left and right).
The NICAM signals must be processed by a deempha-
sis filter and adjusted in level. The analog demodu-
lated signals must be processed by a deemphasis fil-
ter, adjusted in level, and dematrixed. The correct
deemphasis filters are already selected by setting the
standard in the STANDARD SELECT register. The
level adjustment has to be done by means of the FM/
AM and NICAM prescale registers. The necessary
dematrix function depends on the selected sound stan-
dard and the actual broadcasted sound mode (mono,
stereo, or bilingual). It can be manually set by the FM
Matrix Mode register or automatically set by the Auto-
matic Sound Selection.
– “Stereo or B” channel: Analog or digital mono
sound, stereo if available. In case of bilingual broad-
cast, it contains language B (on left and right).
Fig 2–2 shows the source channel assignment of the
demodulated signals in case of manual mode. If man-
ual mode is required, more information can be found in
the section “Demodulator Source Channels in Manual
Mode” on page 96. Fig 2–3 and Table 2–2 show the
source channel assignment of the demodulated sig-
nals in case of Automatic Sound Select mode for all
sound standards.
Note: The analog primary input channel contains the
signal of the mono FM/AM carrier or the L+R signal of
the MPX carrier. The secondary input channel contains
the signal of the 2nd FM carrier, the L−R signal of the
MPX carrier, or the SAP signal.
2.2.4. Automatic Sound Select
In the Automatic Sound Select mode, the dematrix
function is automatically selected based on the identifi-
cation information in the STATUS register. No I2C
interaction is necessary when the broadcasted sound
mode changes (e.g. from mono to stereo).
2.3. Preprocessing for SCART and
I2S Input Signals
The demodulator supports the identification check by
switching between mono compatible standards (stan-
dards that have the same FM mono carrier) automati-
cally and non-audible. If B/G-FM or B/G-NICAM is
selected, the MSP will switch between these stan-
dards. The same action is performed for the stan-
dards: D/K1-FM, D/K2-FM, and D/K-NICAM. Switching
is only done in the absence of any stereo or bilingual
identification. If identification is found, the MSP keeps
the detected standard.
The SCART and I2S inputs need only be adjusted in
level by means of the SCART and I2S prescale regis-
ters.
LS Ch.
Matrix
primary
channel
FM/AM
Prescale
FM-Matrix
FM/AM
0
1
Output-Ch.
Matrices
must be set
according
the standard
secondary
channel
In case of high bit-error rates, the MSP 34x1G auto-
matically falls back from digital NICAM sound to ana-
log FM or AM mono.
NICAM A
NICAM B
NICAM
NICAM
(Stereo or A/B)
Prescale
SC2 Ch.
Matrix
Table 2–1 summarizes all actions that take place when
Automatic Sound Select is switched on.
Fig. 2–2: Source channel assignment of demodulated
signals in Manual Mode
To provide more flexibility, the Automatic Sound Select
block prepares four different source channels of
demodulated sound (Fig 2–3). By choosing one of the
four demodulator channels, the preferred sound mode
can be selected for each of the output channels (loud-
speaker, headphone, etc.). This is done by means of
the Source Select registers.
LS Ch.
Matrix
primary
channel
FM/AM
0
1
FM/AM
Prescale
secondary
channel
Automatic
Sound
Select
Output-Ch.
Matricesmust
be set once to
stereo
Stereo or A/B
The following source channels of demodulated sound
are defined:
NICAM A
NICAM B
NICAM
Stereo or A
Stereo or B
3
4
– “FM/AM” channel: Analog mono sound, stereo if
available. In case of NICAM, analog mono only
(FM or AM mono).
Prescale
SC2 Ch.
Matrix
Fig. 2–3: Source channel assignment of demodulated
signals in Automatic Sound Select Mode
– “Stereo or A/B” channel: Analog or digital mono
sound, stereo if available. In case of bilingual broad-
cast, it contains both languages A (left) and B
(right).
MICRONAS INTERMETALL
11
MICRONAS [ MICRONAS ]
