Functional Description - Compaq Armada e500 Series Reference Manual

6
chapter
A S
UDIO UBSYSTEM
The Armada E500 and Armada V300 computers have an internal, industry-standard
audio controller, the Maestro 2E from ESS Technology. It supports 16-bit stereo audio,
wavetable synthesis, and four-operator FM music synthesis. The Maestro 2E provides
all digital sound creation and reproduction tasks and uses an AC97-compatible CODEC,
the ES1921, as its interface to the analog world.
The Maestro 2E can record, compress, and play back voice, sound, and music with
built-in mixer controls. It consists of an embedded microprocessor, 16-bit stereo A/D
and D/A, 64-voice wavetable synthesizer, 20-voice FM music synthesizer, DMA
control, and ISA bus interface logic. The Maestro 2E also takes the PC speaker output
and converts it to an analog signal with volume control.

Functional Description

The ESS Maestro 2E PCI audio accelerator (M2E), a high-performance
500-MIPS-equivalent PCI audio processor, uses the high-bandwidth PCI bus and an
AC'97 CODEC to deliver advanced PC audio features. These features include HRTF 3-
D positional audio, high-quality 64-channel wavetable music synthesis with
downloadable wavetable samples, and DVD AC-3 5.1-to-2 speaker virtualization.
The device, shown in Figure 6-1, implements multistream DirectSound and
DirectSound3D acceleration and Windows 95 and Windows 98 stream acceleration with
digital mixing and sample rate conversion. The M2E maintains full DOS legacy audio
compatibility over a standard PCI 2.1 bus. The M2E is designed for high-performance
consumer multimedia PC, notebook PC, and add-in card applications.
Based on a dual-engine, 64-channel, pipelined wave processor and a programmable
audio signal processor, the M2E provides simultaneous support for multiple audio
streams of different types. Its core architecture is designed to handle complex signal
processing tasks with a bus-mastering PCI interface and a built-in dedicated DMA
engine supporting a DSP core. The support functions ensure efficient transfer of audio
data streams to and from system memory buffers, providing a system solution with
maximum performance and minimal host CPU loading. The architecture enables
implementation of communications over the Internet from multiple sources.
Audio Subsystem 6-1