STV8216 datasheet(26/97 Pages) STMICROELECTRONICS

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Audio Matrices

STV82x6

26/97

4.1

Input Audio Matrix

The mono input (MONOIN) and three stereo SCART inputs (AI1L, AIR1), (AI2L, AI2R) and (AI3L,

AI3R) can be switched to any audio output and the same source can be connected to different

outputs. The inputs can totally bypass the STV82x6 functions (Thru mode) via the full analog

SCART path or use the audio processing corresponding to the different audio outputs. The input

matrix is programmed in bits DSP_ISCART_SEL[1:0] of register ANA_SCART.

In Thru mode, the STV82x6 is switched into Low Power mode (Standby) and the audio matrix

configuration (ANA_SCART register) is memorized and is not reset when switched back to Full

Power mode. See Section 7.2: Standby Mode.

Before processing the audio signal, the selected analog input is converted into a digital 16-bit signal

and pre-processed. Its sound level can be prescaled within a range between -6 dB and +6 dB in

steps of 1 dB (register PRE_AUX) and for Left/Right channels (register CH_MX). The internal level

can be measured with the Peak Level Detector.

4.2

Output Audio Matrix

The Loudspeaker+Subwoofer (LSL, LSR, SW), Headphone (HPL, HPR) and I²S (SDO) outputs can

directly select two possible sources which are either the demodulated signal or the converted audio

input (from the SCART or mono input) in register CH_SEL. In the event of a dual mono source, the

language is selected in register CH_LANG.

The two analog SCART outputs (AO1L, AO1R) and (AO2L, AO2R) can be used to bypass the

STV82x6 functions by directly selecting the analog input SCARTs or the output digital source from

the demodulator or the converted audio input (with prescaling and Left/Right re-matrixing). The

SCART output is selected in register ANA_SCART and the digital source in register CH_SEL. In the

event of a dual mono source, the language is selected in register CH_LANG as other audio outputs.

In the event of a demodulator source selection, the mute is automatically controlled for all audio

outputs.

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