From: Marcelina Kościelnicka Date: Sat, 4 Jul 2020 21:09:00 +0000 (+0200) Subject: clkbufmap: improve input pad handling. X-Git-Tag: working-ls180~397 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=32d2cc8c285682c3d9613ea0f116679c816b7ac1;p=yosys.git clkbufmap: improve input pad handling. - allow inserting only the input pad cell - do not insert the usual buffer if the input pad already acts as a buffer --- diff --git a/passes/techmap/clkbufmap.cc b/passes/techmap/clkbufmap.cc index 4e9b910db..1cbd12e3d 100644 --- a/passes/techmap/clkbufmap.cc +++ b/passes/techmap/clkbufmap.cc @@ -34,33 +34,34 @@ void split_portname_pair(std::string &port1, std::string &port2) } struct ClkbufmapPass : public Pass { - ClkbufmapPass() : Pass("clkbufmap", "insert global buffers on clock networks") { } + ClkbufmapPass() : Pass("clkbufmap", "insert clock buffers on clock networks") { } void help() override { // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| log("\n"); log(" clkbufmap [options] [selection]\n"); log("\n"); - log("Inserts global buffers between nets connected to clock inputs and their drivers.\n"); + log("Inserts clock buffers between nets connected to clock inputs and their drivers.\n"); log("\n"); log("In the absence of any selection, all wires without the 'clkbuf_inhibit'\n"); - log("attribute will be considered for global buffer insertion.\n"); + log("attribute will be considered for clock buffer insertion.\n"); log("Alternatively, to consider all wires without the 'buffer_type' attribute set to\n"); log("'none' or 'bufr' one would specify:\n"); log(" 'w:* a:buffer_type=none a:buffer_type=bufr %%u %%d'\n"); log("as the selection.\n"); log("\n"); log(" -buf :\n"); - log(" Specifies the cell type to use for the global buffers\n"); + log(" Specifies the cell type to use for the clock buffers\n"); log(" and its port names. The first port will be connected to\n"); log(" the clock network sinks, and the second will be connected\n"); - log(" to the actual clock source. This option is required.\n"); + log(" to the actual clock source.\n"); log("\n"); log(" -inpad :\n"); log(" If specified, a PAD cell of the given type is inserted on\n"); log(" clock nets that are also top module's inputs (in addition\n"); - log(" to the global buffer).\n"); + log(" to the clock buffer, if any).\n"); log("\n"); + log("At least one of -buf or -inpad should be specified.\n"); } void module_queue(Design *design, Module *module, std::vector &modules_sorted, pool &modules_processed) { @@ -78,7 +79,7 @@ struct ClkbufmapPass : public Pass { void execute(std::vector args, RTLIL::Design *design) override { - log_header(design, "Executing CLKBUFMAP pass (inserting global clock buffers).\n"); + log_header(design, "Executing CLKBUFMAP pass (inserting clock buffers).\n"); std::string buf_celltype, buf_portname, buf_portname2; std::string inpad_celltype, inpad_portname, inpad_portname2; @@ -109,8 +110,8 @@ struct ClkbufmapPass : public Pass { extra_args(args, argidx, design); } - if (buf_celltype.empty()) - log_error("The -buf option is required.\n"); + if (buf_celltype.empty() && inpad_celltype.empty()) + log_error("Either the -buf option or -inpad option is required.\n"); // Cell type, port name, bit index. pool>> sink_ports; @@ -118,6 +119,16 @@ struct ClkbufmapPass : public Pass { dict>, pair> inv_ports_out; dict>, pair> inv_ports_in; + // If true, use both ther -buf and -inpad cell for input ports that are clocks. + bool buffer_inputs = true; + + Module *inpad_mod = design->module(RTLIL::escape_id(inpad_celltype)); + if (inpad_mod) { + Wire *buf_wire = inpad_mod->wire(RTLIL::escape_id(buf_portname)); + if (buf_wire && buf_wire->get_bool_attribute(ID::clkbuf_driver)) + buffer_inputs = false; + } + // Process submodules before module using them. std::vector modules_sorted; pool modules_processed; @@ -242,19 +253,30 @@ struct ClkbufmapPass : public Pass { // Clock network not yet buffered, driven by one of // our cells or a top-level input -- buffer it. - log("Inserting %s on %s.%s[%d].\n", buf_celltype.c_str(), log_id(module), log_id(wire), i); - RTLIL::Cell *cell = module->addCell(NEW_ID, RTLIL::escape_id(buf_celltype)); - Wire *iwire = module->addWire(NEW_ID); - cell->setPort(RTLIL::escape_id(buf_portname), mapped_wire_bit); - cell->setPort(RTLIL::escape_id(buf_portname2), iwire); - if (wire->port_input && !inpad_celltype.empty() && module->get_bool_attribute(ID::top)) { + Wire *iwire = nullptr; + RTLIL::Cell *cell = nullptr; + bool is_input = wire->port_input && !inpad_celltype.empty() && module->get_bool_attribute(ID::top); + if (!buf_celltype.empty() && (!is_input || buffer_inputs)) { + log("Inserting %s on %s.%s[%d].\n", buf_celltype.c_str(), log_id(module), log_id(wire), i); + cell = module->addCell(NEW_ID, RTLIL::escape_id(buf_celltype)); + iwire = module->addWire(NEW_ID); + cell->setPort(RTLIL::escape_id(buf_portname), mapped_wire_bit); + cell->setPort(RTLIL::escape_id(buf_portname2), iwire); + } + if (is_input) { log("Inserting %s on %s.%s[%d].\n", inpad_celltype.c_str(), log_id(module), log_id(wire), i); RTLIL::Cell *cell2 = module->addCell(NEW_ID, RTLIL::escape_id(inpad_celltype)); - cell2->setPort(RTLIL::escape_id(inpad_portname), iwire); + if (iwire) { + cell2->setPort(RTLIL::escape_id(inpad_portname), iwire); + } else { + cell2->setPort(RTLIL::escape_id(inpad_portname), mapped_wire_bit); + cell = cell2; + } iwire = module->addWire(NEW_ID); cell2->setPort(RTLIL::escape_id(inpad_portname2), iwire); } - buffered_bits[mapped_wire_bit] = make_pair(cell, iwire); + if (iwire) + buffered_bits[mapped_wire_bit] = make_pair(cell, iwire); if (wire->port_input) { input_bits.insert(i); diff --git a/tests/techmap/clkbufmap.ys b/tests/techmap/clkbufmap.ys index b81a35e74..abe830109 100644 --- a/tests/techmap/clkbufmap.ys +++ b/tests/techmap/clkbufmap.ys @@ -1,5 +1,7 @@ read_verilog <