sdf: Framework for writing out SDF files

Signed-off-by: David Shah <dave@ds0.me>

1 files changed, 200 insertions, 0 deletions

diff --git a/common/sdf.cc b/common/sdf.cc
new file mode 100644
index 00000000..570b8aee
--- /dev/null
+++ b/common/sdf.cc
@@ -0,0 +1,200 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2019  David Shah <dave@ds0.me>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "nextpnr.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+namespace SDF {
+
+struct MinMaxTyp
+{
+    double min, typ, max;
+};
+
+struct RiseFallDelay
+{
+    MinMaxTyp rise, fall;
+};
+
+struct PortAndEdge
+{
+    std::string port;
+    ClockEdge edge;
+};
+
+struct IOPath
+{
+    std::string from, to;
+    RiseFallDelay delay;
+};
+
+struct TimingCheck
+{
+    enum CheckType
+    {
+        SETUPHOLD,
+        PERIOD,
+        WIDTH
+    } type;
+    PortAndEdge from, to;
+    RiseFallDelay delay;
+};
+
+struct Cell
+{
+    std::string celltype, instance;
+    std::vector<IOPath> iopaths;
+    std::vector<TimingCheck> checks;
+};
+
+struct CellPort
+{
+    std::string cell, port;
+};
+
+struct Interconnect
+{
+    CellPort from, to;
+    RiseFallDelay delay;
+};
+
+struct SDFWriter
+{
+    std::vector<Cell> cells;
+    std::vector<Interconnect> conn;
+    std::string sdfversion, design, vendor, program;
+
+    std::string format_name(const std::string &name)
+    {
+        std::string fmt = "\"";
+        for (char c : name) {
+            if (c == '\\' || c == '\"')
+                fmt += "\"";
+            fmt += c;
+        }
+        fmt += "\"";
+        return fmt;
+    }
+
+    std::string timing_check_name(TimingCheck::CheckType type)
+    {
+        switch (type) {
+        case TimingCheck::SETUPHOLD:
+            return "SETUPHOLD";
+        case TimingCheck::PERIOD:
+            return "PERIOD";
+        case TimingCheck::WIDTH:
+            return "WIDTH";
+        default:
+            NPNR_ASSERT_FALSE("unknown timing check type");
+        }
+    }
+
+    void write_delay(std::ostream &out, const RiseFallDelay &delay)
+    {
+        write_delay(out, delay.rise);
+        out << " ";
+        write_delay(out, delay.fall);
+    }
+
+    void write_delay(std::ostream &out, const MinMaxTyp &delay)
+    {
+        out << "(" << delay.min << ":" << delay.typ << ":" << delay.max << ")";
+    }
+
+    void write_port(std::ostream &out, const CellPort &port) { out << format_name(port.cell + "/" + port.port); }
+
+    void write_portedge(std::ostream &out, const PortAndEdge &pe)
+    {
+        out << "(" << (pe.edge == RISING_EDGE ? "posedge" : "negedge") << " " << pe.port << ")";
+    }
+
+    void write(std::ostream &out)
+    {
+        out << "(DELAYFILE" << std::endl;
+        // Headers and  metadata
+        out << "  (SDFVERSION " << format_name(sdfversion) << ")" << std::endl;
+        out << "  (DESIGN " << format_name(design) << ")" << std::endl;
+        out << "  (VENDOR " << format_name(vendor) << ")" << std::endl;
+        out << "  (PROGRAM " << format_name(program) << ")" << std::endl;
+        out << "  (DIVIDER /)" << std::endl;
+        out << "  (TIMESCALE 1ps)" << std::endl;
+        // Write cells
+        for (auto &cell : cells) {
+            out << "  (CELL" << std::endl;
+            out << "    (CELLTYPE " << format_name(cell.celltype) << ")" << std::endl;
+            out << "    (INSTANCE " << format_name(cell.instance) << ")" << std::endl;
+            // IOPATHs (combinational delay and clock-to-q)
+            if (!cell.iopaths.empty()) {
+                out << "    (DELAY" << std::endl;
+                out << "      (ABSOLUTE" << std::endl;
+                for (auto &path : cell.iopaths) {
+                    out << "        (IOPATH " << path.from << " " << path.to << " ";
+                    write_delay(out, path.delay);
+                    out << ")" << std::endl;
+                }
+                out << "      )" << std::endl;
+                out << "    )" << std::endl;
+            }
+            // Timing Checks (setup/hold, period, width)
+            if (!cell.checks.empty()) {
+                out << "    (TIMINGCHECK" << std::endl;
+                for (auto &check : cell.checks) {
+                    out << "      (" << timing_check_name(check.type) << " ";
+                    write_portedge(out, check.from);
+                    out << " ";
+                    if (check.type == TimingCheck::SETUPHOLD) {
+                        write_portedge(out, check.to);
+                        out << " ";
+                    }
+                    if (check.type == TimingCheck::SETUPHOLD)
+                        write_delay(out, check.delay);
+                    else
+                        write_delay(out, check.delay.rise);
+                    out << ")" << std::endl;
+                }
+                out << "    )" << std::endl;
+            }
+            out << "    )" << std::endl;
+        }
+        // Write interconnect delays, with the main design begin a "cell"
+        out << "  (CELL" << std::endl;
+        out << "    (CELLTYPE " << format_name(design) << ")" << std::endl;
+        out << "    (DELAY" << std::endl;
+        out << "      (ABSOLUTE" << std::endl;
+        for (auto &ic : conn) {
+            out << "        (INTERCONNECT ";
+            write_port(out, ic.from);
+            out << " ";
+            write_port(out, ic.to);
+            out << " ";
+            write_delay(out, ic.delay);
+            out << std::endl;
+        }
+        out << "      )" << std::endl;
+        out << "    )" << std::endl;
+        out << "  )" << std::endl;
+        out << ")" << std::endl;
+    }
+};
+
+} // namespace SDF
+
+NEXTPNR_NAMESPACE_END
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