MSP 34x2G
PRELIMINARY DATA SHEET
3.3.2.1. STANDARD SELECT Register
3.3.2.2. Refresh of STANDARD SELECT Register
The TV sound standard of the MSP 34x2G demodula-
tor is determined by the STANDARD SELECT register.
There are two ways to use the STANDARD SELECT
register:
A general refresh of the STANDARD SELECT register
is not allowed. However, the following method
enables watching the MSP 34x2G “alive” status and
detection of accidental resets (only versions A2 and
later):
– Setting up the demodulator for a TV sound standard
by sending the corresponding standard code with a
single I2C-Bus transmission.
– After Power-on, bit[15] of CONTROL will be set; it
must be read once to enable the reset-detection
feature.
– Starting the Automatic Standard Detection for ter-
restrial TV standards. This is the most comfortable
way to set up the demodulator. Within 0.5 s, the
detection and set-up of the actual TV sound stan-
dard is performed. The detected standard can be
read out of the STANDARD RESULT register by the
control processor. This feature is recommended for
the primary set-up of a TV set. Outputs should be
muted during Automatic Standard Detection.
– Reading of the CONTROL register and checking
the reset indicator bit[15] .
– If bit[15] is “0”, any refresh of the STANDARD
SELECT register is not allowed.
– If bit[15] is “1”, indicating a reset, a refresh of the
STANDARD SELECT register and all other MSPG
registers is necessary.
The Standard Codes are listed in Table 3–7.
3.3.2.3. STANDARD RESULT Register
Selecting a TV sound standard via the STANDARD
SELECT register initializes the demodulator. This
includes: AGC-settings and carrier mute, tuning fre-
quencies, FIR-filter settings, demodulation mode (FM,
AM, NICAM), deemphasis and identification mode.
If Automatic Standard Detection is selected in the
STANDARD SELECT register, status and result of the
Automatic Standard Detection process can be read out
of the STANDARD RESULT register. The possible
results are based on the mentioned Standard Code
and are listed in Table 3–8.
TV stereo sound standards that are unavailable for a
specific MSP version are processed in analog mono
sound of the standard. In that case, stereo or bilingual
processing will not be possible.
In cases where no sound standard has been detected
(no standard present, too much noise, strong interfer-
ers, etc.) the STANDARD RESULT register contains 00
00hex. In that case, the controller has to start further
actions (for example, set the standard according to a
preference list or by manual input).
For a complete setup of the TV sound processing from
analog IF input to the source selection, the transmis-
sions as shown in Section 3.5. are necessary.
For reasons of software compatibility to the
MSP 34x0D, a Manual/Compatibility mode is available.
A detailed description of this mode can be found on
page 85.
As long as the STANDARD RESULT register contains
a value greater than 07 FFhex, the Automatic Standard
Detection is still active. During this period, the MODUS
and STANDARD SELECT register must not be written.
The STATUS register will be updated when the Auto-
matic Standard Detection has finished.
If a present sound standard is unavailable for a specific
MSP version, it detects and switches to the analog
mono sound of this standard.
Example:
The MSP 3442G will detect a B/G-NICAM signal as
standard 3 and will switch to the analog FM-Mono
sound.
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Micronas
MICRONAS [ MICRONAS ]
