Real Forward Lattice All-Pole IIR (Embedded Target for Texas Instruments C6000 DSPs)

Embedded Target for Texas Instruments C6000 DSPs

Filter a real input signal using an autoregressive forward lattice filter

Library

C62x DSP Library--Filtering

Description

The 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 four, and they must be in reversed order. Use an even number of reflection coefficients to maximize the speed of your generated code.

The Real Forward Lattice All-Pole IIR block supports discrete sample times and both little-endian and big-endian code generation.

Dialog Box

Coefficient source: Specify the source of the filter coefficients:

Specify via dialog--Enter the coefficients in the Reflection coefficients parameter in the dialog
Input port--Accept the coefficients from port K

Reflection coefficients: Designate the reflection coefficients of the filter in vector format. The number of coefficients must be greater than or equal to four, and they must be in reverse order. Use an even number of reflection coefficients to maximize the speed of your generated code. This parameter is only visible when Specify via dialog is selected for the Coefficient source parameter. This parameter is tunable in simulation.
Initial conditions: If the 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 of this vector must be one less than the number of coefficients.
Different across channels, enter a matrix containing all initial conditions. The number of rows of this matrix must be one less than the number of coefficients, and the number of columns of this matrix must be equal to the number of channels.

Algorithm

In simulation, the Real Forward Lattice All-Pole IIR block is equivalent to the TMS320C62x DSP Library assembly code function DSP_iirlat. During code generation, this block calls the DSP_iirlat routine to produce optimized code.

See Also

Real IIR

Radix-8 Real FIR Real IIR