tda9874aps NXP Semiconductors, tda9874aps Datasheet - Page 45

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

Philips Semiconductors
7.4.1
Table 73 Device status register (subaddress 0)
Table 74 Description of the device status register bits
2000 Aug 04
Digital TV sound demodulator/decoder
P2IN
BIT
7
7
6
5
4
3
2
1
0
D
EVICE
S
SYMBOL
AMSTAT
TATUS
IDDUA
IDSTE
RSSF
VDSP
P1IN
P2IN
P1IN
PFR
6
R
EGISTER
Input from Port 2: this bit reflects the status of the general purpose port pin P2;
see Section 7.3.3. If bit P2IN = 1 the general purpose port pin P2 is at HIGH level.
If bit P2IN = 0 the general purpose port pin P2 is at LOW level.
Input from Port 1: this bit reflects the status of the general purpose port pin P1;
see Section 7.3.3. If bit P1IN = 1 then the general purpose port pin P1 is at HIGH level.
If bit P1IN = 0 the general purpose port pin P1 is at LOW level.
Reserve sound switching flag: if bit RSSF = 1 it is a copy of bit C4 in the NICAM status
register (see Section 7.4.2). It indicates that the FM (or AM for standard L) sound
matches the digital transmission and auto-muting should be enabled. If bit RSSF = 0
auto-muting should be disabled, as analog and digital sound are different.
Auto-mute status: if bit AMSTAT = 1 it indicates that the auto-muting function has
switched from NICAM to the program of the first sound carrier (i.e. FM mono or AM in
NICAM L systems).
Identification of NICAM sound: if bit VDSP = 1 it indicates that digital transmission is a
sound source. If bit VDSP = 0 it indicates that the transmission is either data or a
currently undefined format.
Identification of FM dual sound; A2 systems: if bit IDDUA = 1 an FM dual-language
signal has been identified. When neither bit IDSTE = 1 nor bit IDDUA = 1 the received
signal is assumed to be FM mono (A2 systems only).
Identification of FM stereo; A2 systems: if bit IDSTE = 1 an FM stereo signal has been
identified (A2 systems only).
Power failure register: the power supply for the digital part of the device (V
temporarily been lower than the specified lower limit. If this is detected an initialization of
the device has to be carried out to ensure reliable operation.
RSSF
(DSR)
5
AMSTAT
4
45
VDSP
3
DESCRIPTION
IDDUA
2
IDSTE
1
Product specification
TDA9874A
DDD1
PFR
) has
0