From 73b87e780798fe2c7958b75e4dfddc0dc2169d20 Mon Sep 17 00:00:00 2001 From: Jim Lawson Date: Mon, 1 Apr 2019 15:02:12 -0700 Subject: [PATCH] Refine memory support to deal with general Verilog memory definitions. --- backends/firrtl/firrtl.cc | 203 ++++++++++++++++++++++++++++++++------ 1 file changed, 173 insertions(+), 30 deletions(-) diff --git a/backends/firrtl/firrtl.cc b/backends/firrtl/firrtl.cc index eef6401b2..ed6e9f8ee 100644 --- a/backends/firrtl/firrtl.cc +++ b/backends/firrtl/firrtl.cc @@ -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_ports; + vector 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 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; -- 2.30.2