Section 7.4.2.2 – Cirrus Logic CS4970x4 User Manual

Page 104

CS4953x4/CS4970x4 DSP Manager API Description

CS4953x4/CS4970x4 System Designer’s Guide

DS810UM6

7-11

x= ppm mode defined for the first module ID (Module 1as defined in DSP_CFG_PPM_MODE1

Table 7-4

) in "ppm modes" section in the flash_image. xml file.

w= ppm mode defined for the second module ID (Module 2 as defined in

DSP_CFG_PPM_MODE1 in

Table 7-4

) in "ppm modes" section in the

flash_image. xml file.

See

Example 1

for sample commands to change decoder module mode changes

Example 1 Sample Commands to Initiate Decoder Mode Changes

ucmd Ef00000000000100# Set Configuration Lock

ucmd Ef000007000p00qq# Change decoder mode

ucmd Ef000008000r00ss# Change MPM mode

ucmd Ef000009000t00uu# Change VPM mode

ucmd Ef00000A000000vv# Load PPM

ucmd Ef00000B000w000x# Change PPM mode

ucmd Ef00000000000001# Change to new configuration

7.4.2.2 Using DSP Condenser to Change the Audio Input Source

The user can issue commands to change the input source based on following formats:

w= input source (Refer to DSP_CFG_AUDIO_SRC in

Table 7-4

For example: w = 2 for HDMI with autodetect

w = 3 MULTICHANNEL ANALOG INPUT

xxxx =

DSP_CFG_MCLK_FACTOR in

Table 7-4

For example:

xxxx = 0200 for HDMI since MCLK is 24 MHz (512 Fs when Fs = 48

KHz)

Or,

xxxx = 0100 for SPDIF Inputs since MCLK is 12.288 MHz (256 Fs

when Fs = 48 KHz)

Or,

xxxx= 0200(MCLK = 24MHz) based on the MCLK value for a multi-

channel analog input(512 Fs when Fs = 48 KHz)

The DSP_CFG_MCLK_FACTOR should remain the same for a particular input source, although the
frequency of the MCLK changes. The sample rate configurations in the flash_image.xml file will set the
correct DAO clock values.

For example, If the input stream over HDMI is 96 KHz PCM, the MCLK frequency should remain at 24
MHz and the DSP_CFG_MCLK_FACTOR value (index 0x0013) should remain 0x0200 (512 Fs).
DSP_CFG_MCLK_FACTOR has a direct relation with the frequency of MCLK rather than being a factor of
the sampling frequency, when input the source is HDMI.

Example 2

provides sample commands for changing the audio input source.

Example 2 Sample Commands to Change Audio Input Source

# All of the following commands are mandatory when changing Audio

# Input Sources.

ucmd ef00000000000100# Set Configuration Lock Mode

ucmd ef0000060000000w # Set Audio Input Source

This manual is related to the following products:

CS4953x4