TDA9875A Philips Semiconductors, TDA9875A Datasheet - Page 44

• Manufacturer Part Number: TDA9875A
• Description: Digital TV Sound Processor DTVSP
• Manufacturer: Philips Semiconductors

Philips Semiconductors
10.3.11 NICAM
The decision of whether auto-muting is permitted shall be taken by the controlling microcontroller based on information
contained in the TDA9875A’s status registers. Thus, it depends on the strategy implemented in the software whether the
auto-mute function is in accordance with “NICAM 728 ETS Revised for Data Applications” or any other preference.
The NICAM de-emphasis gain is 0 dB at 40 Hz.
Table 32 Subaddress 14 (note 1)
Notes
1. The default setting at power-up is 0000 0000.
2. The DCXO test mode is intended for checking the DCXO control range with the actually used PCB layout and crystal
1999 Dec 20
Digital TV Sound Processor (DTVSP)
7 (MSB)
0 (LSB)
type. During the normal operating mode, the DCXO test mode should not be used.
BIT
6
5
4
3
2
1
DCXOPULL
DCXOTEST
DOUTEN
CONFIGURATION REGISTER
NDEEM
AMUTE
AMSEL
NAME
B5
VALUE
1
0
1
0
0
1
0
0
1
0
1
0
1
0
Set to lower DCXO frequency during DCXO test mode.
Set to higher DCXO frequency during DCXO test mode.
DCXO test mode on (available only during FM mode); note 2
DCXO normal mode on
Set logic to 0.
Enables the output of the NICAM serial data stream from the DQPSK
demodulator on pin NICAM and of the associated clock on pin PCLK
Both outputs will be 3-stated.
Set logic to 0.
The auto-mute function will switch the output sound from NICAM L to the
ADC output select register. With the ADC output select register the wanted
signal source, e.g. the mono input, can be pre-set (see Section 10.3.20).
This is useful, if the AM sound NICAM L system is demodulated externally.
The auto-mute function will switch the output sound from NICAM L to the
AM program on the internal first sound carrier.
Switches the NICAM J17 de-emphasis off.
Switches the NICAM J17 de-emphasis on.
Automatic muting is disabled. This bit has only an effect when the second
sound carrier is set to NICAM.
Enables the automatic switching between NICAM and the program on the
first sound carrier (i.e. FM mono or AM), dependent on the NICAM bit error
rate.
44
DESCRIPTION
Product specification
TDA9875A