Is there DPI-C compatible types for types?

Question

I was attempting to write a struct compatible with DPI-C for Verilog.

The struct is as follows:

/* Microcontroller FW config */
struct ucode_image_config {
    uintptr_t src_addr;
    uint32_t size;
};

In DPI-C the code is as follows:

/* Microcontroller FW configuration */
typedef struct {
  int unsigned src_addr;
  int unsigned size;
} ucode_image_config_t;

I assume this is not a 1-1 equivalence because of the variable size of uintptr_t, so I'm wondering if there's a better solution.

score 0 · Answer 1 · answered Jul 31 '23 at 19:26

SystemVerilog does not have pointers, so there is no compatible pointer data type between C and SystemVerilog. It does a an opaque pointer called a chandle which allows you to pass a C pointer from one DPI-C routine to another. But there is no way to reference anything using the chandle from the SystemVerilog side without importing another DPI-C access routine.

The DPI has the concept of Open arrays (Section 35.5.6.1 in the IEEE 1800-2017 SystemVerilog LRM. You should take a look at that and probably ask another question giving details on the intent of what you are trying to accomplish.

Is there DPI-C compatible types for types?

1 Answers1