STV0684 datasheet(19/49 Pages) STMICROELECTRONICS

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STV0684

Functional Description

3.6

Audio interface

The STV0684 includes every step of the processing chain required to record, compress,

decompress and playback audio. The STV0684 features a high quality 16 bit sigma delta analog to

digital converter including automatic level control and noise gating, as well as volume control. It also

features an ADPCM CODEC to maximize the length of audio and AVI clips on a given mass storage

media. Finally, the product features a digital to analog converter (PWM followed by RC filters) to

directly address a speaker or buzzer for audio playback.

3.6.1

Audio record

The audio record block consists two main blocks the analogue front end and a 16bit delta-sigma

ADC. The front end includes the functions of automatic level control and noise gate, and volume

control, the ADC uses sampling frequencies of 8kHz, 11.025kHz, 16kHz, 22.05kHz, 32kHz,

44.1kHz and 48kHz, with either differential or single ended inputs. The sampled output can be 8 or

16 bit. The output of the ACD is then available to the ADPCM module giving an audio compression

ratio of 4 to 1.

3.6.2

Audio playback

Audio playback is achieved by an internal Pulse Width Modulator with a sample rates of 8kHz,

11.025kHz, 16kHz, 22.05kHz, 32kHz or 44.1kHz, connected to either an external amplifier chip and

loudspeaker/ head phone socket, or to a simple piezo buzzer.

3.7

TV interface

The TV block is composed of a digital encoder that supports PAL and NTSC and a video digital to

analog converter (DAC). This interface supports still and video encoding for display on a TV set.

Features

● Supports PAL/NTSC analog TV standards

● Interlaced input data, YCrCb 4:2:2 format

● 16bits x 16words FIFO for buffering incoming display data

● Interrupt generation

STV0684 Arkusz danych(PDF) 19 Page - STMicroelectronics