An analog and digital record, playback and processing system using a coarse-fine programming method

A system on chip for conditioning of voiceband analog audio signals and nonvolatile storage for use in mobile communication devices is presented. The system allows for direct interface to acoustic transducer elements and provides signal conditioning to gain adjust, multiplex, filter and mix two independent signals. The system can record these processed signals as analog samples in a nonvolatile flash EEPROM array for later retrieval. Together with the integrated signal path the system can store up to 16 minutes of audio signal. Control of the system is achieved via a serial interface, which is used to configure and control the device. The serial interface can also be used to store digital data into the flash EEPROM array. All necessary components of the system are provided on chip including analog processing elements, nonvolatile storage and high voltage and reference generation.