Cirrus Logic CS4970x4 - Manual (Page 104)

CS4953x4/CS4970x4 DSP Manager API Description
CS4953x4/CS4970x4 System Designer’s Guide
DS810UM6 Copyright 2013 Cirrus Logic, Inc 7-11
x= ppm mode defined for the first module ID (Module 1as defined in DSP_CFG_PPM_MODE1
in 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