CS48500 View Datasheet(PDF) - Cirrus Logic

Part Name

Description

Manufacturer

CS48500

32-bit Audio Decoder DSP Family

Cirrus Logic 

CS48500 Data Sheet

32-bit Audio Decoder DSP Family

3. Code Overlays

The suite of software available for the CS48500 family consists of an operating system (OS) and a library

of overlays. The overlays have been divided into three main groups called Matrix-processors, Virtualizer-

processors, and Post-processors. All software components are defined below:

1. OS/Kernel - Encompasses all non-audio processing tasks, including loading data from external

memory, processing host messages, calling audio-processing subroutines, error concealment, etc.

2. Matrix-processor- Any Module that performs a matrix decode on PCM data to produce more output

channels than input channels (2Ön channels). Examples are Dolby ProLogic IIx and DTS Neo:6.

Generally speaking, these modules increase the number of valid channels in the audio I/O buffer.

3. Virtualizer-processor - Any module that encodes PCM data into fewer output channels than input

channels (nÖ2 channels) with the effect of providing “phantom” speakers to represent the physical audio

T channels that were eliminated. Examples are Dolby Headphone® and Dolby Virtual Speaker®. Generally

F speaking, these modules reduce the number of valid channels in the audio I/O buffer.

4. Post-processors - Any module that processes audio I/O buffer PCM data in-place after the matrix- or

A virtualizer-processors. Examples are bass management, audio manager, tone control, EQ, delay,

customer-specific effects, etc.

R The bulk of each overlay is stored in ROM within the CS48500, but a small image is required to configure

D the overlays and boot the DSP. This small image can either be stored in an external serial

FLASH/EEPROM, or downloaded via a host controller through the SPI™/I2C® serial port.

The overlay structure reduces the time required to reconfigure the DSP when a processing change is

L I requested. Each overlay can be reloaded independently without disturbing the other overlays. For

example, when a new matrix-processor is selected, the OS, virtualizer-, and post-processors do not

IA H need to be reloaded — only the new matrix-processor (the same is true for the other overlays).

Table 2 below lists the firmware available based on device selection. Please refer AN298, CS48500

T P Firmware User’s Manual for the latest listing of application codes and Cirrus Framework™ modules

CONFIDEN DEL available.

DS734A3

©Copyright 2006 Cirrus Logic, Inc.

7

CONFIDENTIAL

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