From f4c62f33ac56bc5725c44ad822e75d2387f98061 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marcin=20Ko=C5=9Bcielnicki?= Date: Mon, 12 Aug 2019 15:57:43 +0000 Subject: Add clock buffer insertion pass, improve iopadmap. A few new attributes are defined for use in cell libraries: - iopad_external_pin: marks PAD cell's external-facing pin. Pad insertion will be skipped for ports that are already connected to such a pin. - clkbuf_sink: marks an input pin as a clock pin, requesting clock buffer insertion. - clkbuf_driver: marks an output pin as a clock buffer output pin. Clock buffer insertion will be skipped for nets that are already driven by such a pin. All three are module attributes that should be set to a comma-separeted list of pin names. Clock buffer insertion itself works as follows: 1. All cell ports, starting from bottom up, can be marked as clock sinks (requesting clock buffer insertion) or as clock buffer outputs. 2. If a wire in a given module is driven by a cell port that is a clock buffer output, it is in turn also considered a clock buffer output. 3. If an input port in a non-top module is connected to a clock sink in a contained cell, it is also in turn considered a clock sink. 4. If a wire in a module is driven by a non-clock-buffer cell, and is also connected to a clock sink port in a contained cell, a clock buffer is inserted in this module. 5. For the top module, a clock buffer is also inserted on input ports connected to clock sinks, optionally with a special kind of input PAD (such as IBUFG for Xilinx). 6. Clock buffer insertion on a given wire is skipped if the clkbuf_inhibit attribute is set on it. --- techlibs/xilinx/synth_xilinx.cc | 37 ++++++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-) (limited to 'techlibs/xilinx/synth_xilinx.cc') diff --git a/techlibs/xilinx/synth_xilinx.cc b/techlibs/xilinx/synth_xilinx.cc index d143c6823..a7362d26b 100644 --- a/techlibs/xilinx/synth_xilinx.cc +++ b/techlibs/xilinx/synth_xilinx.cc @@ -63,6 +63,9 @@ struct SynthXilinxPass : public ScriptPass log(" generate an output netlist (and BLIF file) suitable for VPR\n"); log(" (this feature is experimental and incomplete)\n"); log("\n"); + log(" -ise\n"); + log(" generate an output netlist suitable for ISE\n"); + log("\n"); log(" -nobram\n"); log(" disable inference of block rams\n"); log("\n"); @@ -78,6 +81,12 @@ struct SynthXilinxPass : public ScriptPass log(" -nowidelut\n"); log(" do not use MUXF[78] resources to implement LUTs larger than LUT6s\n"); log("\n"); + log(" -iopads\n"); + log(" perform I/O buffer insertion (selected automatically by -ise)\n"); + log("\n"); + log(" -noiopads\n"); + log(" disable I/O buffer insertion (only useful with -ise)\n"); + log("\n"); log(" -widemux \n"); log(" enable inference of hard multiplexer resources (MUXF[78]) for muxes at or\n"); log(" above this number of inputs (minimum value 2, recommended value >= 5).\n"); @@ -104,7 +113,7 @@ struct SynthXilinxPass : public ScriptPass } std::string top_opt, edif_file, blif_file, family; - bool flatten, retime, vpr, nobram, nodram, nosrl, nocarry, nowidelut, abc9; + bool flatten, retime, vpr, ise, iopads, noiopads, nobram, nodram, nosrl, nocarry, nowidelut, abc9; int widemux; void clear_flags() YS_OVERRIDE @@ -116,6 +125,9 @@ struct SynthXilinxPass : public ScriptPass flatten = false; retime = false; vpr = false; + ise = false; + iopads = false; + noiopads = false; nocarry = false; nobram = false; nodram = false; @@ -178,6 +190,18 @@ struct SynthXilinxPass : public ScriptPass vpr = true; continue; } + if (args[argidx] == "-ise") { + ise = true; + continue; + } + if (args[argidx] == "-iopads") { + iopads = true; + continue; + } + if (args[argidx] == "-noiopads") { + noiopads = true; + continue; + } if (args[argidx] == "-nocarry") { nocarry = true; continue; @@ -410,6 +434,17 @@ struct SynthXilinxPass : public ScriptPass run("clean"); } + if (check_label("finalize")) { + bool do_iopads = iopads || (ise && !noiopads); + if (help_mode || do_iopads) + run("clkbufmap -buf BUFG O:I -inpad IBUFG O:I", "(-inpad passed if '-iopads' or '-ise' and not '-noiopads')"); + else + run("clkbufmap -buf BUFG O:I"); + + if (do_iopads) + run("iopadmap -bits -outpad OBUF I:O -inpad IBUF O:I A:top", "(only if '-iopads' or '-ise' and not '-noiopads')"); + } + if (check_label("check")) { run("hierarchy -check"); run("stat -tech xilinx"); -- cgit v1.2.3 From c6d5b97b98e6edc395ee14ad60430f7ebc264f01 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marcin=20Ko=C5=9Bcielnicki?= Date: Tue, 13 Aug 2019 00:35:54 +0000 Subject: review fixes --- techlibs/xilinx/synth_xilinx.cc | 45 ++++++++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 18 deletions(-) (limited to 'techlibs/xilinx/synth_xilinx.cc') diff --git a/techlibs/xilinx/synth_xilinx.cc b/techlibs/xilinx/synth_xilinx.cc index a7362d26b..e9e8dbfea 100644 --- a/techlibs/xilinx/synth_xilinx.cc +++ b/techlibs/xilinx/synth_xilinx.cc @@ -81,12 +81,15 @@ struct SynthXilinxPass : public ScriptPass log(" -nowidelut\n"); log(" do not use MUXF[78] resources to implement LUTs larger than LUT6s\n"); log("\n"); - log(" -iopads\n"); - log(" perform I/O buffer insertion (selected automatically by -ise)\n"); + log(" -iopad\n"); + log(" enable I/O buffer insertion (selected automatically by -ise)\n"); log("\n"); - log(" -noiopads\n"); + log(" -noiopad\n"); log(" disable I/O buffer insertion (only useful with -ise)\n"); log("\n"); + log(" -noclkbuf\n"); + log(" disable automatic clock buffer insertion\n"); + log("\n"); log(" -widemux \n"); log(" enable inference of hard multiplexer resources (MUXF[78]) for muxes at or\n"); log(" above this number of inputs (minimum value 2, recommended value >= 5).\n"); @@ -113,7 +116,7 @@ struct SynthXilinxPass : public ScriptPass } std::string top_opt, edif_file, blif_file, family; - bool flatten, retime, vpr, ise, iopads, noiopads, nobram, nodram, nosrl, nocarry, nowidelut, abc9; + bool flatten, retime, vpr, ise, iopad, noiopad, noclkbuf, nobram, nodram, nosrl, nocarry, nowidelut, abc9; int widemux; void clear_flags() YS_OVERRIDE @@ -126,8 +129,9 @@ struct SynthXilinxPass : public ScriptPass retime = false; vpr = false; ise = false; - iopads = false; - noiopads = false; + iopad = false; + noiopad = false; + noclkbuf = false; nocarry = false; nobram = false; nodram = false; @@ -194,12 +198,16 @@ struct SynthXilinxPass : public ScriptPass ise = true; continue; } - if (args[argidx] == "-iopads") { - iopads = true; + if (args[argidx] == "-iopad") { + iopad = true; + continue; + } + if (args[argidx] == "-noiopad") { + noiopad = true; continue; } - if (args[argidx] == "-noiopads") { - noiopads = true; + if (args[argidx] == "-noclkbuf") { + noclkbuf = true; continue; } if (args[argidx] == "-nocarry") { @@ -435,14 +443,15 @@ struct SynthXilinxPass : public ScriptPass } if (check_label("finalize")) { - bool do_iopads = iopads || (ise && !noiopads); - if (help_mode || do_iopads) - run("clkbufmap -buf BUFG O:I -inpad IBUFG O:I", "(-inpad passed if '-iopads' or '-ise' and not '-noiopads')"); - else - run("clkbufmap -buf BUFG O:I"); - - if (do_iopads) - run("iopadmap -bits -outpad OBUF I:O -inpad IBUF O:I A:top", "(only if '-iopads' or '-ise' and not '-noiopads')"); + bool do_iopad = iopad || (ise && !noiopad); + if (help_mode || !noclkbuf) { + if (help_mode || do_iopad) + run("clkbufmap -buf BUFG O:I -inpad IBUFG O:I", "(skip if '-noclkbuf', '-inpad' passed if '-iopad' or '-ise' and not '-noiopad')"); + else + run("clkbufmap -buf BUFG O:I"); + } + if (do_iopad) + run("iopadmap -bits -outpad OBUF I:O -inpad IBUF O:I A:top", "(only if '-iopad' or '-ise' and not '-noiopad')"); } if (check_label("check")) { -- cgit v1.2.3 From 49765ec19ea63bff5f04e28e5729d5852a2f8287 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marcin=20Ko=C5=9Bcielnicki?= Date: Tue, 13 Aug 2019 18:05:49 +0000 Subject: minor review fixes --- techlibs/xilinx/synth_xilinx.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'techlibs/xilinx/synth_xilinx.cc') diff --git a/techlibs/xilinx/synth_xilinx.cc b/techlibs/xilinx/synth_xilinx.cc index e9e8dbfea..4069094a6 100644 --- a/techlibs/xilinx/synth_xilinx.cc +++ b/techlibs/xilinx/synth_xilinx.cc @@ -64,7 +64,7 @@ struct SynthXilinxPass : public ScriptPass log(" (this feature is experimental and incomplete)\n"); log("\n"); log(" -ise\n"); - log(" generate an output netlist suitable for ISE\n"); + log(" generate an output netlist suitable for ISE (enables -iopad)\n"); log("\n"); log(" -nobram\n"); log(" disable inference of block rams\n"); -- cgit v1.2.3