Call Legacy Lookup Table Functions Using C Function Block

This example shows how to use the C Function block to call legacy C functions that implement n-dimensional table lookups.

In this example the legacy C functions are defined in lookupTable.h, and implemented in directLookupTableND.c. The type definitions used in this example can be found in your_types.h.

In the model, the header file and the source file are specified in Model Configuration Parameters > Simulation Target. Now the C function can be called in the C Function block. The prototype of the function being called in this example is:

FLT directLookupTableND(const FLT *tableND, const UINT32 nbDims, const UINT32 *tableDims, const UINT32 *tableIdx)

where FLT is a type definition to a floating-point type, and UINT32 is a type definition to an unsigned 32-bit integer.

This example defines two macro functions that use the function directLookupTableND, which are called using the C Function blocks. They are:

• DirectLookupTable3D - 3D lookup table

• DirectLookupTable4D - 4D lookup table

Both these functions take the following input arguments:

• const FLT *tableND - Table

• const UINT32 *tableDims - Size of the table

• const UINT32 *tableIdx - Table index

where the tableND and tableDims are mapped to C Function block parameters and tableIdx is the input to the block. The value returned by the legacy C function is the output of the block.

model = 'slexCFunctionLookupTable';
open_system(model);
sim(model);