STV0674 Functional Description

STV0674

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2.5.3

EEPROM interface

The STV0674 supports up to 512Kbit EEPROM to hold application specific firmware code. Also, in

the case of a tethered only web cam, lower density EEPROMs (down to 1Kbit) can be used to store

information regarding custom USB Product ID, Vendor ID and power consumption.

2.6

Audio record

The audio record block consists of a 16bit delta-sigma ADC using sampling frequencies of 8 kHz,

11.025 kHz, 16 kHz, 22.05 kHz, 32 kHz, 44.1 kHz and 48 kHz, with either differential or single

ended inputs. The sampled output can be 8 or 16 bit.

2.7

Audio playback

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

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

loudspeaker/ headphone socket or to a simple piezo buzzer.

2.8

USB PC interface

The STV0674 includes a USB version 1.1 compliant Universal Serial Bus interface which requires

the minimum of additional hardware. The interface key features are listed here below.

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Compliant with USB protocol revision 1.1

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USB audio class compliant

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USB protocol handling

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USB device state handling

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Clock and data recovery from USB

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Bit stripping and bit stuffing functions

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CRC5 checking, CRC16 generation and checking

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Serial to parallel conversion

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Twin bulk end points (in/out)

USB drivers are supplied by ST. For USB timing information, please refer to the USB specification

version 1.1.

2.9

Power requirements

STV0674 requires a 3V3 supply for I/O and a 1V8 supply for the core.