CS492X

The block diagram on the cover page of this document accurately portrays the interaction between the various generic application modules of the PCM Processing code.

The following should be noted about all values in the application modules:Variables marked by 'Default*' will only be initialized after download. These variables will retain their values after a soft reset or application restart.

Variables marked by 'Default' will be reinitialized to the values shown in this application note after download, soft reset or application restart.Only those values which are presented as valid or which fall within the specified range should be written to the application module variables. If a value which falls outside the stated range is written to a variable, functionality of the application is not guaranteed and erroneous output could result.
 
All bits that are not defined should be considered reserved and written with 0's unless specified otherwise.

For variables such as volume and scaling factors,the real number range of 0.0-1.0 is written as 0x000000-0x7FFFFF. This range is linear, i.e. 1/4 volume, or -12 dB, is represented as 0x1FFFFF and is equivalent to a value of 0.25.

The formula for converting variable settings from a hexadecimal number into dB is as follows:20 * log (variable setting/max value for variable) e.g. 20 * log (0x1FFFFF/0x7FFFFF) == -12 dB Numbers preceded by 0x should be interpreted as hex, and numbers followed by 'b' should be interpreted as binary. All values sent to the CS492X should be converted to hexadecimal.Likewise all values read from the part are in hexadecimal.

This document of CS492X includes a brief description of hardware configuration and in depth descriptions of application messaging protocol,application control modules, and application configuration examples. The main body of this document covers all the commonly used features of each stereo PCM application.

CS492X Additional application notes that cover proprietary Stereo PCM processing such as:SRS CircleSurround™, Logic 7™, and Pacific Microsonics™ HDCD® are available as an appendix to this application note for approved licensees of each corresponding technology.