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.

the decoding/processing algorithms listed below require delivery of PCM or IEC61937-packed,

• 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