ST75C540

ST75C530 and ST75C540 are two super-integrated devices including DSP, Modem and Audio Analog Front Ends and memories for Telephony, Modemand FAX applications.

These ST75C540 can be used for classical applications over POTS lines or over Internet.

The super integration technology allows a significant cost reduction on bill of materials for equipment like High-End phones, INTERNET phones, phone-Fax, INTERNET FAX, ...

The ST75C540 are used with a host processor through a Dual Port RAM allowing the use of any kind of microcontroller (RISC, CISC, General Purpose 8-bit C, ...).

The embedded software includes :
   - handset with listening group capability,
   - full duplex handsfree,
   - voicecoder/decoderat 4.8Kbpsfor staticanswering machine applications and ADPCM 16Kbps, 24Kbps and 32Kbps for high quality message recording,
   - Tone and DTMF generators,
   - Tone and DTMF detectors,
   - FAX up to 14.4Kbps,
   - Data-Modemup to 14.4Kbps (ST75C540 only).

The DSP sofware is extensively user configurable allowing specific functions to be supported like Caller Identifier (CLID) and Second Call Waiting Identifier (SCWID).

The DSP software includes a transparent mode allowing the host controller to access directly the modem Analog Front End and the Audio AFE through the dual Port RAM. This ST75C540 is very useful for hostprocessing modem solutions (or soft modem) where the modulation and the demodulation (V.34, V.90) are done by the application main processor. In transparent mode, the embedded DSP can be used simultaneously with the same samples.

The transparentmode for audio AFE is provided to play audio files or to record voice and/or audio.