TDA9875 Philips Semiconductors, TDA9875 Datasheet - Page 34

• Manufacturer Part Number: TDA9875
• Description: Digital TV Sound Processor DTVSP
• Manufacturer: Philips Semiconductors

Philips Semiconductors
10.3.2
10.3.2.1
Table 13 Description of Table 14
10.3.2.2
Table 14 Subaddress 1 (note 1)
Note
1. The default setting at power-up is 11000000.
1998 Feb 13
AGCSLOW
AGCOFF
7 (MSB)
Digital TV Sound Processor (DTVSP)
SIFSEL
P1OUT,
STDBY
P2OUT
0 (LSB)
NAME
INIT
BIT
6
5
4
3
2
1
G
ENERAL CONFIGURATION REGISTER
Description
Definition
HIGH/LOW
AGCSLOW AGC decay time
AGCOFF
SIFSEL
P2OUT
P1OUT
STDBY
NAME
HIGH
HIGH
HIGH
HIGH
HIGH
LOW
LOW
LOW
LOW
LOW
INIT
X
Selects pin SIF2 for input (recommended for satellite tuner).
Pin SIF1 (terrestrial TV) is selected.
Forces the AGC block to a fixed gain as defined in the AGC gain register.
The automatic gain control function is enabled and the contents of the AGC gain register is
ignored.
A longer decay time and larger hysteresis are selected for input signals with strong video
modulation (intercarrier). This bit only has an effect when bit AGCOFF = 0.
Selects normal attack and decay times for the AGC and a small hysteresis.
Causes initialization of TDA9875 to its default settings. This has the same effect as a
power-on reset. If there is a conflict between the default settings and any bit set HIGH in
this register, the bits of this register have priority over the corresponding default setting.
This bit is automatically reset to LOW after initialization. When set LOW, the TDA9875 is in
its normal mode of operation.
Puts the TDA9875 into the standby mode. Most functions are disabled and power
dissipation is somewhat reduced, but the analog selectors/matrices remain operational to
support analog copying from SCART 1 to SCART 2 and vice versa.
The TDA9875 is in its normal mode of operation. On return from standby mode, the device
is in its power-on reset mode and needs to be re-initialized.
These bits control the general purpose input/output pins. The contents of these bits is
written directly to the corresponding pins. If input is desired, the bits must be set HIGH to
allow the pins to be pulled LOW externally. Input from the pins is reflected in the device
status register (see Section 10.4, subaddress 0). P1OUT is recommended to be used for
switching an SIF trap for the adjacent picture carrier in designs that employ such a trap.
general purpose I/O pin 2
general purpose I/O pin 1
stand-by mode on/off
initialize to defaults (as reset)
don’t care
AGC on/off
SIF input select
34
DESCRIPTION
FUNCTION
Preliminary specification
TDA9875