From 64a5f8f75e99eb9970b69f2d7165c014a57c29cf Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Wed, 20 Nov 2013 21:00:43 +0100
Subject: [PATCH] Added "proc_arst -global_arst" feature
---
passes/proc/proc.cc | 25 ++++++++++++++--
passes/proc/proc_arst.cc | 64 ++++++++++++++++++++++++++++++++++++----
2 files changed, 81 insertions(+), 8 deletions(-)
diff --git a/passes/proc/proc.cc b/passes/proc/proc.cc
index 05f166759..eb99ab005 100644
--- a/passes/proc/proc.cc
+++ b/passes/proc/proc.cc
@@ -28,7 +28,7 @@ struct ProcPass : public Pass {
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
- log(" proc [selection]\n");
+ log(" proc [options] [selection]\n");
log("\n");
log("This pass calls all the other proc_* passes in the most common order.\n");
log("\n");
@@ -41,17 +41,36 @@ struct ProcPass : public Pass {
log("\n");
log("This replaces the processes in the design with multiplexers and flip-flops.\n");
log("\n");
+ log("The following options are supported:\n");
+ log("\n");
+ log(" -global_arst [!]<netname>\n");
+ log(" This option is passed through to proc_arst.\n");
+ log("\n");
}
virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
{
+ std::string global_arst;
+
log_header("Executing PROC pass (convert processes to netlists).\n");
log_push();
- extra_args(args, 1, design);
+ size_t argidx;
+ for (argidx = 1; argidx < args.size(); argidx++)
+ {
+ if (args[argidx] == "-global_arst" && argidx+1 < args.size()) {
+ global_arst = args[++argidx];
+ continue;
+ }
+ break;
+ }
+ extra_args(args, argidx, design);
Pass::call(design, "proc_clean");
Pass::call(design, "proc_rmdead");
- Pass::call(design, "proc_arst");
+ if (global_arst.empty())
+ Pass::call(design, "proc_arst");
+ else
+ Pass::call(design, "proc_arst -global_arst " + global_arst);
Pass::call(design, "proc_mux");
Pass::call(design, "proc_dff");
Pass::call(design, "proc_clean");
diff --git a/passes/proc/proc_arst.cc b/passes/proc/proc_arst.cc
index 021d87c81..65dc97bdd 100644
--- a/passes/proc/proc_arst.cc
+++ b/passes/proc/proc_arst.cc
@@ -196,25 +196,79 @@ struct ProcArstPass : public Pass {
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
- log(" proc_arst [selection]\n");
+ log(" proc_arst [-global_arst [!]<netname>] [selection]\n");
log("\n");
log("This pass identifies asynchronous resets in the processes and converts them\n");
log("to a different internal representation that is suitable for generating\n");
log("flip-flop cells with asynchronous resets.\n");
log("\n");
+ log(" -global_arst [!]<netname>\n");
+ log(" In modules that have a net with the given name, use this net as async\n");
+ log(" reset for registers that have been assign initial values in their\n");
+ log(" declaration ('reg foobar = constant_value;'). Use the '!' modifier for\n");
+ log(" active low reset signals. Note: the frontend stores the default value\n");
+ log(" in the 'init' attribute on the net.\n");
+ log("\n");
}
virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
{
+ std::string global_arst;
+ bool global_arst_neg = false;
+
log_header("Executing PROC_ARST pass (detect async resets in processes).\n");
- extra_args(args, 1, design);
+ size_t argidx;
+ for (argidx = 1; argidx < args.size(); argidx++)
+ {
+ if (args[argidx] == "-global_arst" && argidx+1 < args.size()) {
+ global_arst = args[++argidx];
+ if (!global_arst.empty() && global_arst[0] == '!') {
+ global_arst_neg = true;
+ global_arst = global_arst.substr(1);
+ }
+ global_arst = RTLIL::escape_id(global_arst);
+ continue;
+ }
+ break;
+ }
+
+ extra_args(args, argidx, design);
for (auto &mod_it : design->modules)
if (design->selected(mod_it.second)) {
SigMap assign_map(mod_it.second);
- for (auto &proc_it : mod_it.second->processes)
- if (design->selected(mod_it.second, proc_it.second))
- proc_arst(mod_it.second, proc_it.second, assign_map);
+ for (auto &proc_it : mod_it.second->processes) {
+ if (!design->selected(mod_it.second, proc_it.second))
+ continue;
+ proc_arst(mod_it.second, proc_it.second, assign_map);
+ if (global_arst.empty() || mod_it.second->wires.count(global_arst) == 0)
+ continue;
+ std::vector<RTLIL::SigSig> arst_actions;
+ for (auto sync : proc_it.second->syncs)
+ if (sync->type == RTLIL::SyncType::STp || sync->type == RTLIL::SyncType::STn)
+ for (auto &act : sync->actions) {
+ RTLIL::SigSpec arst_sig, arst_val;
+ for (auto &chunk : act.first.chunks)
+ if (chunk.wire && chunk.wire->attributes.count("\\init")) {
+ RTLIL::SigSpec value = chunk.wire->attributes.at("\\init");
+ value.extend(chunk.wire->width, false);
+ arst_sig.append(chunk);
+ arst_val.append(value.extract(chunk.offset, chunk.width));
+ }
+ if (arst_sig.width) {
+ log("Added global reset to process %s: %s <- %s\n",
+ proc_it.first.c_str(), log_signal(arst_sig), log_signal(arst_val));
+ arst_actions.push_back(RTLIL::SigSig(arst_sig, arst_val));
+ }
+ }
+ if (!arst_actions.empty()) {
+ RTLIL::SyncRule *sync = new RTLIL::SyncRule;
+ sync->type = global_arst_neg ? RTLIL::SyncType::ST0 : RTLIL::SyncType::ST1;
+ sync->signal = mod_it.second->wires.at(global_arst);
+ sync->actions = arst_actions;
+ proc_it.second->syncs.push_back(sync);
+ }
+ }
}
}
} ProcArstPass;