This version (30 Jun 2017 10:27) was approved by Venkatesan Krishnamoorthy.The Previously approved version (22 Jun 2012 14:39) is available.Diff

Signal Subtract

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There are two kinds of subtraction supported.

  1. Subtraction (Real Signals)
  2. Subtraction (Complex Signals)

Subtraction (Real Signals)

The Subtract Block performs a subtraction operation on the input pins and outputs the difference result. (Minuend - Subtrahend = Difference)||

Input Pins

NameFormat [int/dec] - [control/audio]Function Description
Input_Pin 0any - anyMinuend term
Input_Pin 1any - anySubtrahend term

Output Pins

NameFormat [int/dec] - [control/audio]Function Description
Input_Pin 0any - anyDifference term

Algorithm Description

A standard subtraction operation is performed. When the algorithm is grown new input pins appear. These input pins represent more subtrahend terms so that the resulting output formula is:
Output_Pin 0 = Input_Pin 0 - (Input_Pin1 + Input_Pin2 + Input_Pin3 + … Input_PinN)


The subtraction block can be used along with other arithmetic operators to realize many typical DSP functions. It is a basic building block that allows difference operations to be performed.

The subtraction block can also be useful when debugging a schematic project. In the following example subtraction is used to compare the output of the Crossover Filter and two separate General 2nd Order filters set-up to do a cross-over functionality. By subtracting the two “low” outputs and the two “high” outputs, you can verify that both filters are the same if the resulting output in the Readback window is 0.

Algorithm Details

Toolbox PathBasic DSP - Arithmetic Operations - Signal Subtract
Cores SupportedADAU144x
“Grow Algorithm” Supportedyes - see Algorithm Growth Information
“Add Algorithm” Supportedno
Subroutine/Loop Basedno
Program RAM3*
Data RAM1
Parameter RAM0

Subtraction (Complex Signals)

This algorithm subtracts the complex signals. (All real parts are subtracted to the first signal's real part and all imaginary parts are subtracted to first signals imaginary part)This is a block based module.

Input Pins

NameFormat [int/dec] - [control/audio]Function Description
Pin 0: Operand 1 complex Input complex signal 1
Pin 1: Operand 2 complex Input Complex signal 2

Output Pins

NameFormat [int/dec] - [control/audio]Function Description
Pin 0: Output Signal Complex Complex output signal

Grow Algorithm

input pins can be grown up to 8 channels.

Supported DSPs

ADAU145x (Block Schematic only)

Example Usage

This can be used to subtract two signals FFT's result as shown below.

resources/tools-software/sigmastudio/toolbox/basicdsp/signalsubtract.txt · Last modified: 09 Mar 2017 07:47 by Venkatesan Krishnamoorthy