STV82X6T datasheet(21/95 Pages) STMICROELECTRONICS

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STV82x6

Audio Processor Block

The Beeper operates in one of two modes:

●

Pulse mode (beep applications) A tone with a programmable short duration (between 128 ms

and 1 s) is generated. Afterwards, the beeper is automatically disabled and the output is

switched back to the audio signal.

●

Continuous mode (alarm application) A tone with a programmable long duration is generated.

Its start and stop controls must be programmed by I²C.

In both modes, it is recommended to use the mute function to smooth the audio-to-beeper and

beeper-to-audio (Continuous mode only) transitions. The second transition is automatically muted

in Pulse mode. Beeper parameters are controlled in register BEEPER_CTRL.

The beeper tone level and frequency are programmed in register BEEPER_TONE. The level (or

volume) ranges between 0 dB and -93 dB in steps of 3 dB and the tone frequency ranges between

62.2 Hz and 8 kHz in steps of 1 octave.

A beep generator is shared only by the Loudspeaker or Headphone outputs. Therefore, in the event

of simultaneous beeps when in Pulse mode, only the first beep will define the effective duration that

will be the same for both outputs.

Note:

The audio output is not affected by the Automatic Mute Control of Automatic Standard Recognition

function when the beeper is activated.

3.10

SRS™ 3D Surround (STV8226/36 only)

In addition to ST WideSurround, the STV8226/36 provides SRS™ 3D Stereo and Mono outputs

which are spatial effects patented by SRS Labs. The SRS™ system is available on the IC when the

SRS_ON bit of register CUT_ID is set (STV8226/36 identification). ST and SRS™ Surround

systems cannot be used simultaneously. These signals are output only on the Loudspeaker path.

Figure 12: Pulse Mode

Figure 13: Continuous Mode

0.125s < T < 1s

62.5 Hz < F < 8 kHz

BEEP_ON = 1

BEEP_ON = 0

T predefined

62.5 Hz < F < 8 kHz

BEEP_ON = 1

BEEP_ON = 0

T defined by I²C write

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