stv8226t STMicroelectronics, stv8226t Datasheet - Page 27

• Manufacturer Part Number: stv8226t
• Description: Multistandard Tv Audio Processor And Digital Sound Demodulator
• Manufacturer: STMicroelectronics

STV82x6
5
5.1
5.2
5.3
5.4
STV82x6
Additional Controls and Flags
Interrupt Request
The identified TV sound standard is displayed in register AUTO_STAT. Each change in the detected
standard is flagged to the host system via hardware pin IRQ. The flag must be reset by re-
programming the IRQ bit in register
by reading registers AUTO_STAT, NICAM_STAT, ZWT_STAT and CH_MX.
I²C Bus Expander
Pins BUS0 and BUS1 can be used to control external switchable IF SAW filters or audio switches.
These pins can be directly programmed by register CTRL.
Stereo Flag
For Loudspeakers only, a Stereo Mode Detection flag (the ST_ID bit in register AUTO_STAT) is set
when a demodulated source is selected and a stereo standard is detected. The stereo flag is also
output on pin ST in order to control an external indicator (e.g. LED). The stereo mode is also
displayed by status register AUTO_STAT.
CAUTION: When the I²S input is selected, the stereo flag is no longer available on pin ST.
Headphone Detection
For the headphone, the HPD input can be used to automatically mute the Loudspeaker and
Subwoofer outputs when the HPD_ON bit is set in register
must be set for the mute function to be active.
I²C Control
Mute Control
Figure 16: Headphone Detection
AUTO_CTRL
Audio Processing
Audio Processing
Audio Processing
Loudspeaker
Subwoofer
Headphone
and then checking the detected standard status
ANA_LS_HP
Additional Controls and Flags
Headphone
Detection
(active low). The HPD pin
Sub-
woofer
Right
Left
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