SAA7284GP Philips Semiconductors, SAA7284GP Datasheet - Page 14

• Manufacturer Part Number: SAA7284GP
• Description: Terrestrial digital sound decoder for conventional intercarrier PLL-IF systems
• Manufacturer: Philips Semiconductors

Philips Semiconductors
DAIE
When set HIGH this bit switches in the Digital Audio
Interface output to the DOBM pin. When set LOW the
DOBM output is 3-stated. Power-on resets to HIGH.
FM3
These bits set the level of attenuation of the FM audio
signal (see Table 9). Power-on resets 0000 = 0 dB
attenuation.
ASYS
When this bit is HIGH it activates the automatic standard
switch mode. When set LOW, the standard must be set by
the BG/I bit. Power-on resets to HIGH.
BG/I
When this bit is HIGH it switches the DQPSK demodulator
to system BGH and attenuates the digital audio level by
Table 5 Output as a function of M1/M2 and DMSEL
Table 7 SSWIT signal states and function
Note
1. Where X = don’t care.
1996 Oct 24
SSWIT3
DMSEL
Terrestrial digital sound decoder for
conventional intercarrier PLL-IF systems
0
0
1
1
0
0
0
0
1
1
TO
FM0
SSWIT2
M1/M2
X
0
1
0
1
X
0
0
1
1
(1)
selects DIGITAL; L = M2, R = M2
selects DIGITAL; L = M1, R = M1
selects DIGITAL; L = M2, R = M1
selects DIGITAL; L = M1, R = M2
SSWIT1
0
1
0
1
0
1
FUNCTION
NICAM source de-emphasis switched out, no gain
NICAM source de-emphasis switched in, no gain
NICAM source de-emphasis switched in, +6 dB gain; power-on reset when
PORA = HIGH
NICAM source de-emphasis switched in, +12 dB gain; power-on reset when
PORA = LOW
external inputs switched in, no change to previous de-emphasis/gain setting
FM inputs switched in, no change to previous de-emphasis/gain setting
14
4.6 dB (if NICLEV is set HIGH). When LOW, the DQPSK
demodulator switches to system I (with no 4.6 dB
attenuation). Power-on resets to HIGH.
NICLEV
When this bit is set LOW it overrides the 4.6 dB NICAM
audio level compensation, irrespective of whether the
device is in automatic or manual system mode. When set
HIGH the 4.6 dB compensation level is applied in
system BGH. Power-on resets to HIGH.
STLOCK
When STLOCK is set HIGH it will stop the automatic
system switch after the device has achieved an INSYNC
condition, should the demodulator lose lock at any time.
This minimizes the re-acquisition time. When set LOW the
device will be permitted to change system after an
INSYNC condition has been reached. Power-on resets to
LOW.
Table 6 Port 2 control
PORT2
FUNCTION
0
1
PIN OUTPUT STATE
Preliminary specification
HIGH
LOW
SAA7284