|
|
|
| R2012a Documentation → Embedded Coder | |
Learn more about Embedded Coder |
|
| Contents | Index |
Embedded Coder/ Embedded Targets/ Processors/ Texas Instruments C6000/ Optimization/ C64x DSP Library
The C64x Real Forward Lattice All-Pole IIR block filters a real input signal using an autoregressive forward lattice filter. The input and output signals must be the same 16-bit signed fixed-point data type. The reflection coefficients must be real and Q.15. The number of reflection coefficients must be greater than or equal to ten; they must be even; and they must be in reversed order — k(n), k(n-1),..., k(0). Using an even number of reflection coefficients maximizes the speed of your generated code.
The Real Forward Lattice All-Pole IIR block supports discrete sample times and supports little-endian code generation only.
Specify the source of the filter coefficients:
Specify via dialog — Enter the coefficients in the Reflection coefficients parameter in the dialog box
Input port — Accept the coefficients from port K
Designate the reflection coefficients of the filter in vector format. The number of coefficients must be greater than or equal to ten and be even. Enter the coefficients in reverse order from k(n) to k(0). Using an even number of reflection coefficients maximizes the speed of your generated code. This parameter is visible when you select Specify via dialog for the Coefficient source parameter. This parameter is tunable in simulation.
If your block initial conditions are
All the same, you need only enter a scalar.
Different within channels but the same across channels, enter a vector containing the initial conditions for one channel. The length (number of elements) of this vector must be the same as the number of reflection coefficients in your filter.
Different across channels, enter a matrix containing all initial conditions. The number of rows (initial conditions for one channel) of this matrix must be the same as the number of reflection coefficients, and the number of columns of this matrix must be equal to the number of channels.
Process input signal as frames or samples
Columns as channels (frame based) — Process the input signal as frames. Each frame contains a group of sequential data samples. To perform frame-based processing, you must have a DSP System Toolbox license.
Elements as channels (sample based) — Process the input signal as individual data samples.
Inherited (this choice will be removed — see release notes) — Use the frame status attribute of the input signal to determine whether to process the input as frames or samples.
When you load an existing model in R2011a, the software sets this parameter to Inherited (this choice will be removed - see release notes). Selecting this option allows you to continue working with your model until you upgrade. Upgrade your model using the slupdate function as soon as possible.
Note For more information about this option, see Changes to Frame-Based Processing |
In simulation, the Real Forward Lattice All-Pole IIR block is equivalent to the TMS320C64x DSP Library assembly code function DSP_iirlat. During code generation, this block calls the DSP_iirlat routine to produce optimized code.
Learn more about Simulink through this collection of videos, articles, technical literature and the Getting Started with Simulink Guide.
| © 1984-2012- The MathWorks, Inc. - Site Help - Patents - Trademarks - Privacy Policy - Preventing Piracy - RSS |
