diff --git a/docs/finn/verification.rst b/docs/finn/verification.rst index 391c6f999312839daca0d4161336c7c0ae822f89..c52c0840aa40566d930164490b1fd249d7c07757 100644 --- a/docs/finn/verification.rst +++ b/docs/finn/verification.rst @@ -28,4 +28,15 @@ This simulation can be used for a model containing several HLS custom operations Emulation using PyVerilator =========================== -The emulation using PyVerilator can be used when IP blocks were generated, either node by node or of a whole design. For that purpose PyVerilator gets the generated verilog files. +The emulation using PyVerilator can be used when IP blocks were generated, either node by node or of a whole (IP-stitched) design. For that purpose PyVerilator gets the generated verilog files. + +For debugging purposes, it's possible to generate .vcd trace files that show the value of external & internal signals as the emuation is running. To enable this: + - for node-by-node rtlsim, set the `rtlsim_trace` attribute of each node of interest to either a file name for the vcd or `default` to use the node name as the filename. + - for IP-stitched rtlsim, set the `rtlsim_trace` metadata_prop for the graph as per above. + +To control the tracing depth in the module hierarchy, use the `RTLSIM_TRACE_DEPTH` environment variable (default is 1): + - level 1 shows top-level input/output streams + - level 2 shows per-layer input/output streams + - level 3 shows per full-layer I/O including FIFO count signals + +Note that deeper tracing will take longer to execute and may produce very large .vcd files.