Single-Chip PC Sound System

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Single-Chip PC Sound System

The AD1812*SoundPort Controller is a single-chip audio sub-system for adding 16-bit stereo audio to personal computers. The ISA Plug and Play (PnP) system is compatible with applications written for Windows 95, the Microsoft Windows® Sound System, Sound Blaster Pro® and Ad Lib®, and provides an MPU-compatible interface and a game port complete with timer.otp voice chip

ISA PnP Interface:

The chip is complete with all necessary PnP bus interface logic. This includes address decoding for on-board resources, control and signal interpretation, DMA selection and control logic, IRQ selection and control logic, all interface configuration logic. The AD1812 can support two, or three DMA channels. Included are dual DMA count registers for full-duplex operation, enabling simultaneous capture and playback on separate DMA channels. The AD1812 is configurable according to the Plug and Play ISA Specification. Table 1 lists the logical devices supported by the AD1812 that ROM coded in its PnP space. For a non-Plug and Play environment, the built in PnP services allow theAD1812 to operate under a user-defined fixed address space.
The built-in 16-bit SoundPort® Stereo Codec supports business audio and multimedia applications. The codec includes stereo audio converters, complete on-chip filtering, an MPC Level-2- compliant analog mixer, and FIFOs for buffering the ISA The pair of 16-bit outputs from the ADCs are available over a bit bidirectional interface that also supplies 16-bit digital data

to the DACs. The codec can accept and generate 16-bit twos-complement PCM linear (big-endian or little-endian) digital data, 4-bit IMA-ADPCM compatible digital data, 8-bit unsigned magnitude PCM linear data, and 8-bit m-law or A-law companded digital data..

Multimedia Support:

The SoundPort Controller combines an embedded 16-bit fixed-point Analog Devices signal processor and dedicated hardware to emulate all Sound Blaster version 2.01 functions. The ROM-coded music synthesis algorithms imitate industry-standard OPL3 FM synthesizer chips and can deliver 20 voice polyphony.