Real IIR (Embedded Target for Texas Instruments C6000 DSPs)

Embedded Target for Texas Instruments C6000 DSPs

Filter a real input signal using a real autoregressive moving-average IIR filter

Library

C62x DSP Library--Filtering

Description

The Real IIR block filters a real input signal X using a real autoregressive moving-average (ARMA) IIR Filter. This filter is implemented using a direct form I structure.

There must be five AR coefficients and five MA coefficients. The first AR coefficient is always assumed to be one. Inputs, coefficients, and output are Q.15 data types.

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

Dialog Box

Coefficient sources: Specify the source of the filter coefficients:

Specify via dialog--Enter the coefficients in the MA (numerator) coefficients and AR (denominator) coefficients parameters in the dialog
Input ports--Accept the coefficients from ports MA and AR

MA (numerator) coefficients: Designate the moving-average coefficients of the filter in vector format. There must be five MA coefficients. This parameter is only visible when Specify via dialog is selected for the Coefficient sources parameter. This parameter is tunable in simulation.
AR (denominator) coefficients: Designate the autoregressive coefficients of the filter in vector format. There must be five AR coefficients, however the first AR coefficient is assumed to be equal to one. This parameter is only visible when Specify via dialog is selected for the Coefficient sources parameter. This parameter is tunable in simulation.
Input state initial conditions: If the input state 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 input state initial conditions for one channel. The length of this vector must be four.
Different across channels, enter a matrix containing all input state initial conditions. This matrix must have four rows.

Output state initial conditions: If the output state 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 output state initial conditions for one channel. The length of this vector must be four.
Different across channels, enter a matrix containing all output state initial conditions. This matrix must have four rows.

Algorithm

In simulation, the Real IIR block is equivalent to the TMS320C62x DSP Library assembly code function DSP_iir. During code generation, this block calls the DSP_iir routine to produce optimized code.

See Also

Real Forward Lattice All-Pole IIR

Real Forward Lattice All-Pole IIR Reciprocal