Compaq 850 manual Audio Controller

Chapter 5 Input/Output Interfaces

5.8.2 AUDIO CONTROLLER

The Creative Technology, Ltd. Ensoniq ES1373 Audio Controller is a PCI device that includes the following features:

♦Compatible with software written for Sound Blaster 128

♦64-Voice wavetable synthesizer

♦4000+ sound library

♦Tone control and speaker equalization

♦Multiple sampling rate support up to 48 KHz

♦OPL-FM and MPU-401 emulation support

♦Supports Ensoniq’s 3D Positional Audio algorithm

♦Aureal A3D API support

♦Microsoft DirectSound, DirectSound 3D, DirectMusic support

♦DOS game compatibility

♦AC’97 Link Bus

♦S/PDIF output

♦ACPI power management

The ES1373 audio controller operates as a PCI bus master and slave device that includes an integrated cache designed to handle the memory bandwidth requirements of audio processing. System memory is accessed as required to keep output cache full (during playback) and input cache (relatively) empty (during record) in accordance with the needs of the audio codec. The integrated cache memory stores playback/record data, sample rate converter data, and control register data. A virtual 3-channel DMA controller handles cache memory operations.

The control registers are accessed using programmed I/O on the PCI bus. All register reads are done as long words, while register writes are performed in byte word or long word format.

In addition to the AC’97 link bus, the audio controller provides a Sony/Philips Digital Interface (SPDIF) output that is applied to the tip connection of the headphone/line out jack. The SPDIF signal format (also known as IEC-958) is a stereo digital signal specification becoming common to consumer products.

5-28Compaq Deskpro EXS and Workstation 300 Personal Computers Featuring the Intel Pentium 4 Processor

First Edition – December 2000