This version (18 Jul 2022 08:21) was approved by Harsha J K.

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Audio Signal Router

Audio Signal Router

Audio Signal Router Ext-Index

Audio Signal Router with Index Selectable


Audio Signal router mixes M different inputs to N different outputs with various gains. The number of input and output pins are configurable.


Audio Signal Router module supports multiple mixer configurations. Each mixer configuration has gains for all the inputs and outputs. A separate gain is available for each of input output combination also. All the gains has a corresponding mute control to quickly mute the particular gain. The current Tab selected (Tab #) in the mixer window is downloaded to the target and used for mixing.
Audio Signal Router ExtIndex functionality is same as audio signal router except that the current mixer (Tab #) is selected through an external input. The control pin expects the input in (32.0) format for ADAU145x processors and (28.0) format for other Sigma DSPs.
Audio Signal Router with Index Selectable- The current mixer (Table Mix) can be changed during the runtime.


  1. Audio Signal Router
  2. Audio Signal Router ExtIndex
  3. Audio Signal Router - Control Index

Targets Supported

Name ADSP-214xx ADSP-215xx/SC5xx ADAU145x/146x
Audio Signal Router BBS
Audio Signal Router ExtIndex BBS
Audio Signal Router Index Selectable NANAS



ExtIndexControlExternal Index input(Only for AudioSignalRouterExtIndex)
InputXAudioInput channel X


OutputX Audio Output Channel X


  • X - Channel Index

Configurable Parameters

GUI Parameter NameDefault ValueRangeFunction Description
InputGain_InputChannel00-138 to 24Scales the input Gain in dB
InputGainMute_InputChannel0falsetrue/falseInput gain enable or mute
OutputGain_OutputChannel00-138 to 24Scales the output Gain in dB
OutputGainMute_OutputChannel0falsetrue/falseoutput gain enable or mute
CrossGain_Input0_Output00-138 to 24Scales cross Gain in dB
CrossGainMute_Input0_Output0falsetrue/falseCross gain enable or mute
NumInputs220Number of input channels. Change in this value requires re-compilation
NumOutputs120Number of Output channels. Change in this value requires re-compilation
SlewRate121 to 24Scales the Step size

DSP Parameters

Parameter Name Description ADSP-214xx/SC5xx/215xx ADAU145x/146x
SlewStepSlew rate Float FixPoint8d24
InputGainArray Input linear gain values Float FixPoint8d24
OutputGainArrayOutput linear gain values Float FixPoint8d24
CrossGainArrayCross linear gain values Float FixPoint8d24
TableIndex Current selected tab index NA Int32
TableIndexMax/TabCount Number of tab count NA Int32
NumCoeffs Total number of coefficient NA Int32

DSP Parameter Computation

LinearGain= 10^(GainArray[i] / 20)
NumCoeffs=(NumInputs* NumOutputs+ NumInputs+ NumOutputs)
tc = 0.04 * Math.Pow(2, SlewRate- 1) / 1000
Alpha = Math.Exp(-1 / (tc * fs))
Om_Alpha = 1 - Alpha

resources/tools-software/sigmastudiov2/modules/mixersandsplitters/audiosignalrouters.txt · Last modified: 18 Jul 2022 08:14 by Harsha J K