tda9874aps NXP Semiconductors, tda9874aps Datasheet - Page 32

• Manufacturer Part Number: tda9874aps
• Description: Digital Tv Sound Demodulator/decoder
• Manufacturer: NXP Semiconductors

Philips Semiconductors
7.3.12
The default setting after Power-on reset is 0000 0000.
Table 38 NICAM configuration register (subaddress 14)
Table 39 Description of the NICAM configuration register 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 bit AMSEL has only an effect on the analog sound outputs (pins OUTL, OUTR and OUTM). With regard to the
4. The DCXO test mode is intended for checking the DCXO control range with the actually used PCB layout and crystal
2000 Aug 04
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.
digital 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
NICAM C
DCXOTEST
DCXOPULL DCXO frequency select: this bit selects the DCXO lower or upper test frequency during
DCXOTEST DCXO test mode enable: if bit DCXOTEST = 1 it enables the DCXO test mode
SYMBOL
DOUTEN
NDEEM
AMUTE
AMSEL
ONFIGURATION
6
2
S-bus), the auto-mute will only switch between NICAM and the first sound carrier.
DCXO test mode. If bit DCXOPULL = 1 it sets the DCXO to the lower DCXO frequency.
If bit DCXOPULL = 0 it sets the DCXO to its higher frequency.
(available only during FM mode). In this mode frequency pulling via bit DCXOPULL is
enabled. If bit DCXOTEST = 0 it enables normal operation.
this bit is not used and should be set to logic 0
Data output enable: if bit DOUTEN = 1 it enables the output of the NICAM serial data
stream from the DQPSK demodulator and of the associated clock, PCLK.
If bit DOUTEN = 0 both outputs will be 3-stated.
this bit is not used and should be set to logic 0
Auto-mute select: if bit 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 7.3.18). If bit 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: if bit NDEEM = 1 it switches the NICAM J17 de-emphasis off.
If bit NDEEM = 0 it switches the NICAM J17 de-emphasis on.
Auto-muting on/off: if bit AMUTE = 1 automatic muting is disabled. This bit only has an
effect when the second sound carrier is set to NICAM. If bit 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
32
3
0
DESCRIPTION
AMSEL
2
NDEEM
1
Product specification
TDA9874A
AMUTE
0