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Owning Palette: FixedPoint VIs
Requires: Adaptive Filter Toolkit
Configures the settings of a fixedpoint adaptive filter and simulates the performance of this filter. You also can save the fixedpoint adaptive filter settings to an XML file. After you place this Express VI on the block diagram, doubleclick this Express VI to display the configuration dialog box.
After you determine the fixedpoint settings, you can use these settings to generate LabVIEW FPGA code for the fixedpoint adaptive filter.
Dialog Box Options 
Block Diagram Inputs 
Block Diagram Outputs 
Parameter  Description 

Algorithm Settings  Specifies the algorithm settings for the floatingpoint adaptive filter. This Express VI supports only the standard least mean squares (LMS) algorithm. You can choose from the following options:

FixedPoint Configuration  Specifies the settings that you use to simulate a fixedpoint adaptive filter. This section contains the following options:

Save FXP Settings  Saves the fixedpoint settings to an XML file. You can use the AFT Load FixedPoint Settings VI to load the fixedpoint settings from the XML file. 
Parameter  Description 

reset?  Specifies whether to reset the adaptive filter coefficients to zeroes. The default is FALSE. 
x(n)  Specifies the fixedpoint input signal x(n) to the fixedpoint adaptive filter. If you specify a floatingpoint input signal, this Express VI converts the signal into a fixedpoint signal automatically. 
d(n)  Specifies the fixedpoint input signal d(n) to the fixedpoint adaptive filter. If you specify a floatingpoint input signal, this Express VI converts the signal into a fixedpoint signal automatically. 
step size  Specifies the step size value for the fixedpoint adaptive filter. If the value is zero, this VI processes the input signal without updating the coefficients of the adaptive filter. If the value is greater than zero, this VI uses this value as the step size to update the coefficients of the adaptive filter. This value takes precedence over the step size value that you specify for the Step size dialog box option. 
error in (no error)  Describes error conditions that occur before this node runs. 
Parameter  Description 

fixedpoint settings  Returns the fixedpoint adaptive filter settings that you can save to a file in XML format. 
y(n)  Returns the fixedpoint output signal y(n) from the fixedpoint adaptive filter. 
e(n)  Returns the fixedpoint error signal, which is the difference between d(n) and y(n). 
coefficients  Returns the coefficients of the fixedpoint adaptive filter. 
error out  Contains error information. This output provides standard error out functionality. 
simulation information  Returns information about the fixedpoint simulation.

Refer to the following VIs for examples of using the AFT Simulate FixedPoint FIR LMS VI: