backends/verilog: Add support for memory read port reset and init value.

diff --git a/backends/verilog/verilog_backend.cc b/backends/verilog/verilog_backend.cc
index 95ad69c814d664ff37af441ed9ffd43859cb1764..0dc7113bd1699be1ae59a5bc9d0613e066e83acf 100644 (file)
--- a/backends/verilog/verilog_backend.cc
+++ b/backends/verilog/verilog_backend.cc
@@ -515,6 +515,8 @@ void dump_memory(std::ostream &f, std::string indent, Mem &mem)
 
        // create a map : "edge clk" -> expressions within that clock domain
        dict<std::string, std::vector<std::string>> clk_to_lof_body;
+       dict<std::string, std::string> clk_to_arst_cond;
+       dict<std::string, std::vector<std::string>> clk_to_arst_body;
        clk_to_lof_body[""] = std::vector<std::string>();
        std::string clk_domain_str;
        // create a list of reg declarations
@@ -529,8 +531,12 @@ void dump_memory(std::ostream &f, std::string indent, Mem &mem)
                                std::ostringstream os;
                                dump_sigspec(os, port.clk);
                                clk_domain_str = stringf("%sedge %s", port.clk_polarity ? "pos" : "neg", os.str().c_str());
-                               if( clk_to_lof_body.count(clk_domain_str) == 0 )
-                                       clk_to_lof_body[clk_domain_str] = std::vector<std::string>();
+                               if (port.arst != State::S0) {
+                                       std::ostringstream os2;
+                                       dump_sigspec(os2, port.arst);
+                                       clk_domain_str += stringf(", posedge %s", os2.str().c_str());
+                                       clk_to_arst_cond[clk_domain_str] = os2.str();
+                               }
                        }
                        if (!port.transparent)
                        {
@@ -542,22 +548,51 @@ void dump_memory(std::ostream &f, std::string indent, Mem &mem)
                                std::string temp_id = next_auto_id();
                                lof_reg_declarations.push_back( stringf("reg [%d:0] %s;\n", port.data.size() - 1, temp_id.c_str()) );
 
-                               bool has_en = port.en != State::S1;
+                               bool has_indent = false;
 
-                               if (has_en)
-                               {
+                               if (port.arst != State::S0) {
+                                       std::ostringstream os;
+                                       os << stringf("%s <= ", temp_id.c_str());
+                                       dump_sigspec(os, port.arst_value);
+                                       os << ";\n";
+                                       clk_to_arst_body[clk_domain_str].push_back(os.str());
+                               }
+
+                               if (port.srst != State::S0 && !port.ce_over_srst) {
+                                       std::ostringstream os;
+                                       os << stringf("if (");
+                                       dump_sigspec(os, port.srst);
+                                       os << stringf(")\n");
+                                       clk_to_lof_body[clk_domain_str].push_back(os.str());
+                                       std::ostringstream os2;
+                                       os2 << stringf("%s" "%s <= ", indent.c_str(), temp_id.c_str());
+                                       dump_sigspec(os2, port.srst_value);
+                                       os2 << ";\n";
+                                       clk_to_lof_body[clk_domain_str].push_back(os2.str());
+                                       std::ostringstream os3;
+                                       if (port.en == State::S1) {
+                                               os3 << "else begin\n";
+                                       } else {
+                                               os3 << "else if (";
+                                               dump_sigspec(os3, port.en);
+                                               os3 << ") begin\n";
+                                       }
+                                       clk_to_lof_body[clk_domain_str].push_back(os3.str());
+                                       has_indent = true;
+                               } else if (port.en != State::S1) {
                                        std::ostringstream os;
                                        os << stringf("if (");
                                        dump_sigspec(os, port.en);
                                        os << stringf(") begin\n");
                                        clk_to_lof_body[clk_domain_str].push_back(os.str());
+                                       has_indent = true;
                                }
 
                                for (int sub = 0; sub < (1 << port.wide_log2); sub++)
                                {
                                        SigSpec addr = port.sub_addr(sub);
                                        std::ostringstream os;
-                                       if (has_en)
+                                       if (has_indent)
                                                os << indent;
                                        os << temp_id;
                                        if (port.wide_log2)
@@ -568,9 +603,35 @@ void dump_memory(std::ostream &f, std::string indent, Mem &mem)
                                        clk_to_lof_body[clk_domain_str].push_back(os.str());
                                }
 
-                               if (has_en)
+                               if (port.srst != State::S0 && port.ce_over_srst)
+                               {
+                                       std::ostringstream os;
+                                       if (has_indent)
+                                               os << indent;
+                                       os << stringf("if (");
+                                       dump_sigspec(os, port.srst);
+                                       os << stringf(")\n");
+                                       clk_to_lof_body[clk_domain_str].push_back(os.str());
+                                       std::ostringstream os2;
+                                       if (has_indent)
+                                               os2 << indent;
+                                       os2 << stringf("%s" "%s <= ", indent.c_str(), temp_id.c_str());
+                                       dump_sigspec(os2, port.srst_value);
+                                       os2 << ";\n";
+                                       clk_to_lof_body[clk_domain_str].push_back(os2.str());
+                               }
+
+                               if (has_indent)
                                        clk_to_lof_body[clk_domain_str].push_back("end\n");
 
+                               if (!port.init_value.is_fully_undef())
+                               {
+                                       std::ostringstream os;
+                                       dump_sigspec(os, port.init_value);
+                                       std::string line = stringf("initial %s = %s;\n", temp_id.c_str(), os.str().c_str());
+                                       clk_to_lof_body[""].push_back(line);
+                               }
+
                                {
                                        std::ostringstream os;
                                        dump_sigspec(os, port.data);
@@ -765,8 +826,19 @@ void dump_memory(std::ostream &f, std::string indent, Mem &mem)
                if( clk_domain != "")
                {
                        f << stringf("%s" "always%s @(%s) begin\n", indent.c_str(), systemverilog ? "_ff" : "", clk_domain.c_str());
-                       for(auto &line : lof_lines)
-                               f << stringf("%s%s" "%s", indent.c_str(), indent.c_str(), line.c_str());
+                       bool has_arst = clk_to_arst_cond.count(clk_domain) != 0;
+                       if (has_arst) {
+                               f << stringf("%s%s" "if (%s) begin\n", indent.c_str(), indent.c_str(), clk_to_arst_cond[clk_domain].c_str());
+                               for(auto &line : clk_to_arst_body[clk_domain])
+                                       f << stringf("%s%s%s" "%s", indent.c_str(), indent.c_str(), indent.c_str(), line.c_str());
+                               f << stringf("%s%s" "end else begin\n", indent.c_str(), indent.c_str());
+                               for(auto &line : lof_lines)
+                                       f << stringf("%s%s%s" "%s", indent.c_str(), indent.c_str(), indent.c_str(), line.c_str());
+                               f << stringf("%s%s" "end\n", indent.c_str(), indent.c_str());
+                       } else {
+                               for(auto &line : lof_lines)
+                                       f << stringf("%s%s" "%s", indent.c_str(), indent.c_str(), line.c_str());
+                       }
                        f << stringf("%s" "end\n", indent.c_str());
                }
                else