Cirrus Logic CS4953xx - Manual (Page 5)

CS4953xx Data Sheet
32-bit Audio Decoder DSP Family
DS705F2 5
2.1 Migrating from CS4953x3 to CS4953x4
• The recommended way to boot the DSP for normal operation is “master boot”. Refer to Chapter 1 of the
CS4953x4/CS4970x4 System Designer’s Guide. CS4953x4 supports slave boot mode as well (used for
programming the serial flash with the DSP code, through the SCP2 port).
• CS4953x4 DSPs are only available in 128 pin package.
• The serial flash chip select pin used is pin 14 (GPIO0) for master boot. Cirrus Logic recommends that at
least an 8-Mb serial flash device be used. Refer to CS4953x4/CS4970x4 System Designer’s Guide for a
list of flash types that are currently supported.
• CS4953x4 DSP family supports DSP Condenser and DSP Manager API for runtime control/host
communication. Refer to CS4953x4/CS4970x4 System Designer’s Guide for details.
2.2 Licensing
Licenses are required for all third party audio decoding/processing algorithms, including the application notes.
contact your local Cirrus Sales representative for more information.
3 Code Overlays
The suite of software available for the CS4953xx family consists of an operating system (OS) and a library of
overlays. The overlays have been divided into three main groups called Decoders, Matrix-processors, and
Post-processors. All software components are defined below:
• OS/Kernel - Encompasses all non-audio processing tasks, including loading data from external memory,
processing host messages, calling audio-processing subroutines, error concealment, etc.
• Decoders - Any Module that initially writes data into the audio I/O buffers, e.g. AC-3
™
, DTS, PCM, etc. All
the decoding/processing algorithms listed below require delivery of PCM or IEC61937-packed,
compressed data via I
2
S- or LJ-formatted digital audio to the CS4953xx.
• Matrix-processors - Any module that processes audio I/O buffer PCM data in-place before the Post-
processors. Generally speaking, these modules alter the number of valid channels in the audio I/O buffer
through processes like Virtualization (n
2 channels) or Matrix Decoding (2n channels). Examples are
Dolby ProLogic II, IIx, IIz and DTS Neo:6.
• Post-processors - Any module that processes audio I/O buffer PCM data in-place after the Matrix-
Processors. Examples are Bass Management, Audio Manager, Tone Control, EQ, Delay, Customer-
specific Effects, Dolby Headphone 2 and Dolby Virtual Speaker 2, etc.
The overlay structure reduces the time required to reconfigure the DSP when a processing change is
requested. Each overlay can be reloaded independently without disturbing the other overlays. For example,
when a new decoder is selected, the OS, matrix-, and post-processors do not need to be reloaded — only the
new decoder (the same is true for the other overlays).
Table 2 below lists the firmware available based on device selection. Refer to AN288, CS4953xx/CS497xxx
Firmware User’s Manual for the latest listing of application codes and Cirrus Framework
™
modules available.