Refine memory support to deal with general Verilog memory definitions.
authorJim Lawson <ucbjrl@berkeley.edu>
Mon, 1 Apr 2019 22:02:12 +0000 (15:02 -0700)
committerJim Lawson <ucbjrl@berkeley.edu>
Mon, 1 Apr 2019 22:02:12 +0000 (15:02 -0700)
backends/firrtl/firrtl.cc

index eef6401b23c1d8921e4961c692f0d483730e4ece..ed6e9f8eeea4f0640a4fbaaedb61815d3503685c 100644 (file)
@@ -106,6 +106,95 @@ struct FirrtlWorker
        RTLIL::Design *design;
        std::string indent;
 
+       // Define read/write ports and memories.
+       // We'll collect their definitions and emit the corresponding FIRRTL definitions at the appropriate point in module construction.
+       // For the moment, we don't handle $readmemh or $readmemb.
+       // These will be part of a subsequent PR.
+       struct read_port {
+               string name;
+               bool clk_enable;
+               bool clk_parity;
+               bool transparent;
+               RTLIL::SigSpec clk;
+               RTLIL::SigSpec ena;
+               RTLIL::SigSpec addr;
+               read_port(string name, bool clk_enable, bool clk_parity, bool transparent, RTLIL::SigSpec clk, RTLIL::SigSpec ena, RTLIL::SigSpec addr) : name(name), clk_enable(clk_enable), clk_parity(clk_parity), transparent(transparent), clk(clk), ena(ena), addr(addr) {
+                       // Current (3/13/2019) conventions:
+                       //  generate a constant 0 for clock and a constant 1 for enable if they are undefined.
+                       if (!clk.is_fully_def())
+                               this->clk = SigSpec(RTLIL::Const(0, 1));
+                       if (!ena.is_fully_def())
+                               this->ena = SigSpec(RTLIL::Const(1, 1));
+               }
+               string gen_read(const char * indent) {
+                       string addr_expr = make_expr(addr);
+                       string ena_expr = make_expr(ena);
+                       string clk_expr = make_expr(clk);
+                       string addr_str = stringf("%s%s.addr <= %s\n", indent, name.c_str(), addr_expr.c_str());
+                       string ena_str = stringf("%s%s.en <= %s\n", indent, name.c_str(), ena_expr.c_str());
+                       string clk_str = stringf("%s%s.clk <= asClock(%s)\n", indent, name.c_str(), clk_expr.c_str());
+                       return addr_str + ena_str + clk_str;
+               }
+       };
+       struct write_port : read_port {
+               RTLIL::SigSpec mask;
+               write_port(string name, bool clk_enable, bool clk_parity, bool transparent, RTLIL::SigSpec clk, RTLIL::SigSpec ena, RTLIL::SigSpec addr, RTLIL::SigSpec mask) : read_port(name, clk_enable, clk_parity, transparent, clk, ena, addr), mask(mask) {
+                       if (!clk.is_fully_def())
+                               this->clk = SigSpec(RTLIL::Const(0));
+                       if (!ena.is_fully_def())
+                               this->ena = SigSpec(RTLIL::Const(0));
+                       if (!mask.is_fully_def())
+                               this->ena = SigSpec(RTLIL::Const(1));
+               }
+         string gen_read(const char * /* indent */) {
+                       log_error("gen_read called on write_port: %s\n", name.c_str());
+                       return stringf("gen_read called on write_port: %s\n", name.c_str());
+               }
+               string gen_write(const char * indent) {
+                       string addr_expr = make_expr(addr);
+                       string ena_expr = make_expr(ena);
+                       string clk_expr = make_expr(clk);
+                       string mask_expr = make_expr(mask);
+                       string mask_str = stringf("%s%s.mask <= %s\n", indent, name.c_str(), mask_expr.c_str());
+                       string addr_str = stringf("%s%s.addr <= %s\n", indent, name.c_str(), addr_expr.c_str());
+                       string ena_str = stringf("%s%s.en <= %s\n", indent, name.c_str(), ena_expr.c_str());
+                       string clk_str = stringf("%s%s.clk <= asClock(%s)\n", indent, name.c_str(), clk_expr.c_str());
+                       return addr_str + ena_str + clk_str + mask_str;
+               }
+       };
+       /* Memories defined within this module. */
+        struct memory {
+                string name;                                   // memory name
+                int abits;                                             // number of address bits
+                int size;                                              // size (in units) of the memory
+                int width;                                             // size (in bits) of each element
+                int read_latency;
+                int write_latency;
+                vector<read_port> read_ports;
+                vector<write_port> write_ports;
+                std::string init_file;
+                std::string init_file_srcFileSpec;
+                memory(string name, int abits, int size, int width) : name(name), abits(abits), size(size), width(width), read_latency(0), write_latency(1), init_file(""), init_file_srcFileSpec("") {}
+                memory() : read_latency(0), write_latency(1), init_file(""), init_file_srcFileSpec(""){}
+                void add_memory_read_port(read_port &rp) {
+                        read_ports.push_back(rp);
+                }
+                void add_memory_write_port(write_port &wp) {
+                        write_ports.push_back(wp);
+                }
+                void add_memory_file(std::string init_file, std::string init_file_srcFileSpec) {
+                        this->init_file = init_file;
+                        this->init_file_srcFileSpec = init_file_srcFileSpec;
+                }
+
+        };
+       dict<string, memory> memories;
+
+       void register_memory(memory &m)
+       {
+               memories[m.name] = m;
+       }
+
        void register_reverse_wire_map(string id, SigSpec sig)
        {
                for (int i = 0; i < GetSize(sig); i++)
@@ -116,7 +205,7 @@ struct FirrtlWorker
        {
        }
 
-       string make_expr(const SigSpec &sig)
+       static string make_expr(const SigSpec &sig)
        {
                string expr;
 
@@ -515,6 +604,7 @@ struct FirrtlWorker
                                int abits = cell->parameters.at("\\ABITS").as_int();
                                int width = cell->parameters.at("\\WIDTH").as_int();
                                int size = cell->parameters.at("\\SIZE").as_int();
+                               memory m(mem_id, abits, size, width);
                                int rd_ports = cell->parameters.at("\\RD_PORTS").as_int();
                                int wr_ports = cell->parameters.at("\\WR_PORTS").as_int();
 
@@ -531,33 +621,24 @@ struct FirrtlWorker
                                if (offset != 0)
                                        log_error("Memory with nonzero offset: %s.%s\n", log_id(module), log_id(cell));
 
-                               cell_exprs.push_back(stringf("    mem %s:\n", mem_id.c_str()));
-                               cell_exprs.push_back(stringf("      data-type => UInt<%d>\n", width));
-                               cell_exprs.push_back(stringf("      depth => %d\n", size));
-
-                               for (int i = 0; i < rd_ports; i++)
-                                       cell_exprs.push_back(stringf("      reader => r%d\n", i));
-
-                               for (int i = 0; i < wr_ports; i++)
-                                       cell_exprs.push_back(stringf("      writer => w%d\n", i));
-
-                               cell_exprs.push_back(stringf("      read-latency => 0\n"));
-                               cell_exprs.push_back(stringf("      write-latency => 1\n"));
-                               cell_exprs.push_back(stringf("      read-under-write => undefined\n"));
-
                                for (int i = 0; i < rd_ports; i++)
                                {
                                        if (rd_clk_enable[i] != State::S0)
                                                log_error("Clocked read port %d on memory %s.%s.\n", i, log_id(module), log_id(cell));
 
+                                       SigSpec addr_sig = cell->getPort("\\RD_ADDR").extract(i*abits, abits);
                                        SigSpec data_sig = cell->getPort("\\RD_DATA").extract(i*width, width);
-                                       string addr_expr = make_expr(cell->getPort("\\RD_ADDR").extract(i*abits, abits));
-
-                                       cell_exprs.push_back(stringf("    %s.r%d.addr <= %s\n", mem_id.c_str(), i, addr_expr.c_str()));
-                                       cell_exprs.push_back(stringf("    %s.r%d.en <= UInt<1>(1)\n", mem_id.c_str(), i));
-                                       cell_exprs.push_back(stringf("    %s.r%d.clk <= asClock(UInt<1>(0))\n", mem_id.c_str(), i));
-
-                                       register_reverse_wire_map(stringf("%s.r%d.data", mem_id.c_str(), i), data_sig);
+                                       string addr_expr = make_expr(addr_sig);
+                                       string name(stringf("%s.r%d", m.name.c_str(), i));
+                                       bool clk_enable = false;
+                                       bool clk_parity = true;
+                                       bool transparency = false;
+                                       SigSpec ena_sig = RTLIL::SigSpec(RTLIL::State::S1, 1);
+                                       SigSpec clk_sig = RTLIL::SigSpec(RTLIL::State::S0, 1);
+                                       read_port rp(name, clk_enable, clk_parity, transparency, clk_sig, ena_sig, addr_sig);
+                                       m.add_memory_read_port(rp);
+                                       cell_exprs.push_back(rp.gen_read(indent.c_str()));
+                                       register_reverse_wire_map(stringf("%s.data", name.c_str()), data_sig);
                                }
 
                                for (int i = 0; i < wr_ports; i++)
@@ -568,9 +649,16 @@ struct FirrtlWorker
                                        if (wr_clk_polarity[i] != State::S1)
                                                log_error("Negedge write port %d on memory %s.%s.\n", i, log_id(module), log_id(cell));
 
-                                       string addr_expr = make_expr(cell->getPort("\\WR_ADDR").extract(i*abits, abits));
-                                       string data_expr = make_expr(cell->getPort("\\WR_DATA").extract(i*width, width));
-                                       string clk_expr = make_expr(cell->getPort("\\WR_CLK").extract(i));
+                                       string name(stringf("%s.w%d", m.name.c_str(), i));
+                                       bool clk_enable = true;
+                                       bool clk_parity = true;
+                                       bool transparency = false;
+                                       SigSpec addr_sig =cell->getPort("\\WR_ADDR").extract(i*abits, abits);
+                                       string addr_expr = make_expr(addr_sig);
+                                       SigSpec data_sig =cell->getPort("\\WR_DATA").extract(i*width, width);
+                                       string data_expr = make_expr(data_sig);
+                                       SigSpec clk_sig = cell->getPort("\\WR_CLK").extract(i);
+                                       string clk_expr = make_expr(clk_sig);
 
                                        SigSpec wen_sig = cell->getPort("\\WR_EN").extract(i*width, width);
                                        string wen_expr = make_expr(wen_sig[0]);
@@ -579,13 +667,50 @@ struct FirrtlWorker
                                                if (wen_sig[0] != wen_sig[i])
                                                        log_error("Complex write enable on port %d on memory %s.%s.\n", i, log_id(module), log_id(cell));
 
-                                       cell_exprs.push_back(stringf("    %s.w%d.addr <= %s\n", mem_id.c_str(), i, addr_expr.c_str()));
-                                       cell_exprs.push_back(stringf("    %s.w%d.data <= %s\n", mem_id.c_str(), i, data_expr.c_str()));
-                                       cell_exprs.push_back(stringf("    %s.w%d.en <= %s\n", mem_id.c_str(), i, wen_expr.c_str()));
-                                       cell_exprs.push_back(stringf("    %s.w%d.mask <= UInt<1>(1)\n", mem_id.c_str(), i));
-                                       cell_exprs.push_back(stringf("    %s.w%d.clk <= asClock(%s)\n", mem_id.c_str(), i, clk_expr.c_str()));
+                                       SigSpec mask_sig = RTLIL::SigSpec(RTLIL::State::S1, 1);
+                                       write_port wp(name, clk_enable, clk_parity, transparency, clk_sig, wen_sig[0], addr_sig, mask_sig);
+                                       m.add_memory_write_port(wp);
+                                       cell_exprs.push_back(stringf("%s%s.data <= %s\n", indent.c_str(), name.c_str(), data_expr.c_str()));
+                                       cell_exprs.push_back(wp.gen_write(indent.c_str()));
                                }
+                               register_memory(m);
+                               continue;
+                       }
 
+                       if (cell->type.in("$memwr", "$memrd", "$meminit"))
+                       {
+                               std::string cell_type = fid(cell->type);
+                               std::string mem_id = make_id(cell->parameters["\\MEMID"].decode_string());
+                               memory *mp = nullptr;
+                               if (cell->type == "$meminit" ) {
+                                       log_error("$meminit (%s.%s.%s) currently unsupported\n", log_id(module), log_id(cell), mem_id.c_str());
+                               } else {
+                                       // It's a $memwr or $memrd. Remember the read/write port parameters for the eventual FIRRTL memory definition.
+                                       auto addrSig = cell->getPort("\\ADDR");
+                                       auto dataSig = cell->getPort("\\DATA");
+                                       auto enableSig = cell->getPort("\\EN");
+                                       auto clockSig = cell->getPort("\\CLK");
+                                       Const clk_enable = cell->parameters.at("\\CLK_ENABLE");
+                                       Const clk_polarity = cell->parameters.at("\\CLK_POLARITY");
+
+                                       mp = &memories.at(mem_id);
+                                       int portNum = 0;
+                                       bool transparency = false;
+                                       string data_expr = make_expr(dataSig);
+                                       if (cell->type.in("$memwr")) {
+                                               portNum = (int) mp->write_ports.size();
+                                               write_port wp(stringf("%s.w%d", mem_id.c_str(), portNum), clk_enable.as_bool(), clk_polarity.as_bool(),  transparency, clockSig, enableSig, addrSig, dataSig);
+                                               mp->add_memory_write_port(wp);
+                                               cell_exprs.push_back(stringf("%s%s.data <= %s\n", indent.c_str(), wp.name.c_str(), data_expr.c_str()));
+                                               cell_exprs.push_back(wp.gen_write(indent.c_str()));
+                                       } else if (cell->type.in("$memrd")) {
+                                               portNum = (int) mp->read_ports.size();
+                                               read_port rp(stringf("%s.r%d", mem_id.c_str(), portNum), clk_enable.as_bool(), clk_polarity.as_bool(),  transparency, clockSig, enableSig, addrSig);
+                                               mp->add_memory_read_port(rp);
+                                               cell_exprs.push_back(rp.gen_read(indent.c_str()));
+                                               register_reverse_wire_map(stringf("%s.data", rp.name.c_str()), dataSig);
+                                       }
+                               }
                                continue;
                        }
 
@@ -763,6 +888,24 @@ struct FirrtlWorker
 
                f << stringf("\n");
 
+               // If we have any memory definitions, output them.
+               for (auto kv : memories) {
+                       memory m = kv.second;
+                       f << stringf("    mem %s:\n", m.name.c_str());
+                       f << stringf("      data-type => UInt<%d>\n", m.width);
+                       f << stringf("      depth => %d\n", m.size);
+                       for (int i = 0; i < (int) m.read_ports.size(); i += 1) {
+                               f << stringf("      reader => r%d\n", i);
+                       }
+                       for (int i = 0; i < (int) m.write_ports.size(); i += 1) {
+                               f << stringf("      writer => w%d\n", i);
+                       }
+                       f << stringf("      read-latency => %d\n", m.read_latency);
+                       f << stringf("      write-latency => %d\n", m.write_latency);
+                       f << stringf("      read-under-write => undefined\n");
+               }
+               f << stringf("\n");
+
                for (auto str : cell_exprs)
                        f << str;