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authorwhitequark <whitequark@whitequark.org>2020-04-05 10:03:23 +0000
committerwhitequark <whitequark@whitequark.org>2020-04-09 04:08:36 +0000
commit4737f426ff20324316ab037cef719da4b5c520dd (patch)
treea2e80fe8df17fa9fba08a960c61750ecbff6f11d /backends
parent753e34007d64e1bf9d9d5fa19d6a39b328672d88 (diff)
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write_cxxrtl: add basic documentation.
Diffstat (limited to 'backends')
-rw-r--r--backends/cxxrtl/cxxrtl.cc17
1 files changed, 16 insertions, 1 deletions
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 <level>\n");
log(" set the optimization level. the default is -O%d. higher optimization\n", DEFAULT_OPT_LEVEL);