Embedded Target for Texas Instruments C6000 DSPs

Variables and Memory Necessary for Filter Export

When you export a filter by generating a C header file, the header file stores the filter coefficients in filter coefficient variables. You must name these variables in the Export to CCS IDE dialog. Variable names cannot be reserved words of the C programming language, such as if. By generating a program file from the C header file and loading the program file into your target, the filter coefficient variables in the header file appear in the target application symbol table.

When you export a filter by writing directly to target memory, the target stores the filter coefficients in memory locations. These memory locations correspond to filter coefficient variables in the target application symbol table. To export directly to target memory, you specify these variables in the Export to CCS IDE dialog.

The necessary filter coefficient variables depend on the structure of your filter. The Export to CCS IDE dialog provides you with the following parameters to specify or name the necessary filter coefficient variables. The dialog activates only the parameters you need to set; the others become invisible or inactive.

Parameters for Specifying Filter Coefficient Variables	Description
Numerator	Numerator filter coefficients
Numerator length	Number of numerator filter coefficients
Denominator	Denominator filter coefficients
Denominator length	Number of denominator filter coefficients
Lattice coeffs	Lattice coefficients
Lattice coeffs length	Number of lattice coefficients
Ladder coeffs	Ladder coefficients
Ladder coeffs length	Number of ladder coefficients
Number of sections	Number of filter sections (parameter is inactive if your filter has only one section)

In the following table, x marks indicate the parameters you need to set for each filter structure.

Cautions Regarding Writing Directly to Memory

Selecting the Export Data Type