C/RTL Co-Simulation Support - 2021.2 English

The Vitis HLS C/RTL co-simulation feature does not support structures or classes containing hls::stream<> members in the top-level interface. Vitis HLS supports these structures or classes for synthesis.

typedef struct {
   hls::stream<uint8_t> a;
   hls::stream<uint16_t> b;
} strm_strct_t;

void dut_top(strm_strct_t indata, strm_strct_t outdata) { … }

These restrictions apply to both top-level function arguments and globally declared objects. If structs of streams are used for synthesis, the design must be verified using an external RTL simulator and user-created HDL test bench. There are no such restrictions on hls::stream<> objects with strictly internal linkage.