MX802

The MX802 Data/Voice Storage and Retrieval (DVSR) Codec contains a Continuously Variable Slope Delta Modulation (CVSD) encoder and decoder as well as control and timing circuitry for up to 4Mbits of external DRAM. As a member of the DBS800 series, it also contains interface and control logic for the "C-BUS" serial interface.

When used with external DRAM, theMX802 had four primary functions: Speech Storage, Speech layback, Data Storage, and Data Retrieval. The Speech Storage and Playback may be performed concurrently with data storage or retrieval.
On-chip the Delta Codec is supported by input and output analog switched-capacitor filters and audio output switching circuitry. The DRAM control and timing circuitry provides all the necessary address, control, and refresh signals to interface to external DRAM.

The MX802 may also be used without DRAM (as a "stand alone" CVSD Codec), in which case direct access is provided to the CVSD Codec digital data and clock signals. All signals are controlled by "C-BUS" commands from the system microcontroller.

The MX802 may be used with a 5.0V power supply and is available in the following packages: 24-pin PLCC (MX802LH), 28-pin PLCC (MX802LH8), and 28-pin PDIP (MX802P).