Question

This example demonstrates the source compatibility include file svdpi_src.h is not needed if a C function dynamically allocates the data structure for simulator representation of a packed array to be passed to an exported SystemVerilog function.

SystemVerilog:

export "DPI" function myfunc;
...
function void myfunc (output logic [31:0] r); ...
...

C:

#include "svdpi.h"
extern void myfunc (svLogicPackedArrRef r); /* exported from SV */
/* output logic packed 32-bits */
...
svLogicVec32 my_r[SV_CANONICAL_SIZE(32)];
/* my array, canonical representation */
/* allocate memory for logic packed 32-bits in simulator’s representation */
svLogicPackedArrRef r =
(svLogicPackedArrRef)malloc(svSizeOfLogicPackedArr(32));
myfunc(r);
/* canonical <-- actual */
svGetLogicVec32(my_r, r, 32);
/* shall use only the canonical representation from now on */
free(r); /* don’t need any more */
...