From 4737f426ff20324316ab037cef719da4b5c520dd Mon Sep 17 00:00:00 2001 From: whitequark Date: Sun, 5 Apr 2020 10:03:23 +0000 Subject: write_cxxrtl: add basic documentation. --- backends/cxxrtl/cxxrtl.cc | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/backends/cxxrtl/cxxrtl.cc b/backends/cxxrtl/cxxrtl.cc index d204364ca..465882858 100644 --- a/backends/cxxrtl/cxxrtl.cc +++ b/backends/cxxrtl/cxxrtl.cc @@ -1601,7 +1601,22 @@ struct CxxrtlBackend : public Backend { log("\n"); log(" write_cxxrtl [options] [filename]\n"); log("\n"); - log("Write C++ code for simulating the design.\n"); + log("Write C++ code for simulating the design. The generated code requires a driver;\n"); + log("the following simple driver is provided as an example:\n"); + log("\n"); + log(" #include \"top.cc\"\n"); + log("\n"); + log(" int main() {\n"); + log(" cxxrtl_design::p_top top;\n"); + log(" while (1) {\n"); + log(" top.p_clk.next = value<1> {1u};\n"); + log(" top.step();\n"); + log(" top.p_clk.next = value<1> {0u};\n"); + log(" top.step();\n"); + log(" }\n"); + log(" }\n"); + log("\n"); + log("The following options are supported by this backend:\n"); log("\n"); log(" -O \n"); log(" set the optimization level. the default is -O%d. higher optimization\n", DEFAULT_OPT_LEVEL); -- cgit v1.2.3