STV82X7 datasheet(40/156 Pages) STMICROELECTRONICS

40 / 156 page

Dedicated Digital Signal Processor (DSP)

STV82x7

40/156

The beeper tone level and frequency are programmed in register BEEPER_FREQ_VOL. The level

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

between 62.5 Hz and 8 kHz in steps of 1 octave.

A beep generator is shared only by the Loudspeakers 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.

4.16

Internal Audio/Video Delay (Lip Sync)

Since increasing processing on the video signal implies more delay compared to the audio signal,

there is a possibility inside the device of compensating by inserting a delay on the audio path in

order to resynchronize the two signals:

● 60ms with 48 KHz sampling frequency (SCART only input mode)

● 90ms with 32 KHz sampling frequency (demodulator input mode)

The same delay is available for the LS path and/or the HP path.

Figure 22: Pulse Mode

Figure 23: Continuous Mode

62.5 Hz < f < 8 kHz

BEEP_ON = 1

BEEP_ON = 0

T predefined

0.1, 0.25, 0.5 and 1.0 s

62.5 Hz < F < 8 kHz

BEEP_ON = 1

BEEP_ON = 0

T defined by I²C write

STV82X7 数据表(PDF) 40 Page - STMicroelectronics