TDA9874A Philips Semiconductors, TDA9874A Datasheet - Page 40

• Manufacturer Part Number: TDA9874A
• Description: Digital TV sound demodulator/decoder
• Manufacturer: Philips Semiconductors

Philips Semiconductors
10.3.12 NICAM C
The default setting after power-on reset is ‘0000 0000’.
Table 40 NICAM configuration register (subaddress 14)
Table 41 Description of the NCONR bits; see notes 1 to 4
Notes
1. The decision of whether auto-muting is permitted will be taken by the controlling microprocessor based on
2. The NICAM de-emphasis gain is 0 dB at 40 Hz.
3. The AMSEL bit has only an effect on the analog sound outputs (OUTL, OUTR and OUTM). With regard to the digital
4. The DCXO test mode is intended for checking the DCXO control range with the actually used PCB layout and crystal
1999 Dec 03
DCXOPULL
Digital TV sound demodulator/decoder
information contained in the TDA9874A’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.
sound output (I
type. During normal operation, the DCXO test mode should not be used.
BIT
7
7
6
5
4
3
2
1
0
DCXOTEST
DCXOPULL DCXO frequency select: selects DCXO lower or upper test frequency during DCXO
DCXOTEST DCXO test mode enable: when DCXOTEST = 1 it enables the DCXO test mode
SYMBOL
DOUTEN
NDEEM
AMUTE
AMSEL
ONFIGURATION
2
S-bus), the auto-mute will only switch between NICAM and the first sound carrier.
6
test mode. When DCXOPULL = 1 it sets the DCXO to the lower DCXO frequency. When
DCXOPULL = 0 it sets the DCXO to its higher frequency.
(available only during FM mode). In this mode frequency pulling via DCXOPULL is
enabled. When DCXOTEST = 0 it enables normal operation.
this bit is not used and should be set to logic 0
Data output enable: when DOUTEN = 1 it enables the output of the NICAM serial data
stream from the DQPSK demodulator and of the associated clock, PCLK. When
DOUTEN = 0, both outputs will be 3-stated.
this bit is not used and should be set to logic 0
Auto-mute select: when AMSEL = 1 the auto-mute will switch between NICAM sound
and the analog mono input. This bit only has an effect when the auto-mute function is
enabled and when the DAC has been selected in the analog output select register
(see Section 10.3.18). When AMSEL = 0, the auto-mute will switch between NICAM
sound and the sound on the first sound carrier (i.e. FM mono or AM).
De-emphasis on/off: when NDEEM = 1 it switches the NICAM J17 de-emphasis off.
When NDEEM = 0 it switches the NICAM J17 de-emphasis on.
Auto-muting on/off: when AMUTE = 1 automatic muting is disabled. This bit only has
an effect when the second sound carrier is set to NICAM. When AMUTE = 0 it enables
the automatic switching between NICAM and the program on the first sound carrier (i.e.
FM mono or AM), depending on the NICAM bit error rate. The FM dematrix should be
set to the mono position or IDSWFM (subaddress 11) should be set.
R
EGISTER
5
0
(NCONR)
DOUTEN
4
40
3
0
DESCRIPTION
AMSEL
2
NDEEM
Preliminary specification
1
TDA9874A
AMUTE
0