nexus: Lookup speed grade and pip delays

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

2 files changed, 31 insertions, 1 deletions

diff --git a/nexus/arch.cc b/nexus/arch.cc
index 7b4e2041..aff00d5d 100644
--- a/nexus/arch.cc
+++ b/nexus/arch.cc
@@ -137,6 +137,27 @@ Arch::Arch(ArchArgs args) : args(args)
         }
         log_error("Unknown package '%s'. Available package options:%s\n", package.c_str(), all_packages.c_str());
     }
+
+    // Validate and set up speed grade
+
+    // Convert speed to speed grade (TODO: low power back bias mode too)
+    if (speed == "7")
+        speed = "10";
+    else if (speed == "8")
+        speed = "11";
+    else if (speed == "9")
+        speed = "12";
+
+    speed_grade = nullptr;
+    for (size_t i = 0; i < db->num_speed_grades; i++) {
+        auto &sg = db->speed_grades[i];
+        if (sg.name.get() == speed) {
+            speed_grade = &sg;
+            break;
+        }
+    }
+    if (!speed_grade)
+        log_error("Unknown speed grade '%s'.\n", speed.c_str());
 }
 
 // -----------------------------------------------------------------------
diff --git a/nexus/arch.h b/nexus/arch.h
index 88660ca1..93272af8 100644
--- a/nexus/arch.h
+++ b/nexus/arch.h
@@ -307,6 +307,7 @@ NPNR_PACKED_STRUCT(struct CellTimingPOD {
 NPNR_PACKED_STRUCT(struct PipTimingPOD {
     int32_t min_delay;
     int32_t max_delay;
+    // fanout adder seemingly unused by nexus, reserved for future ECP5 etc support
     int32_t min_fanout_adder;
     int32_t max_fanout_adder;
 });
@@ -910,6 +911,7 @@ struct Arch : BaseCtx
     boost::iostreams::mapped_file_source blob_file;
     const DatabasePOD *db;
     const ChipInfoPOD *chip_info;
+    const SpeedGradePOD *speed_grade;
 
     int package_idx;
 
@@ -1275,7 +1277,14 @@ struct Arch : BaseCtx
 
     WireId getPipDstWire(PipId pip) const { return canonical_wire(pip.tile, pip_data(pip).to_wire); }
 
-    DelayInfo getPipDelay(PipId pip) const { return getDelayFromNS(0.1 + (pip.index % 30) / 1000.0); }
+    DelayInfo getPipDelay(PipId pip) const
+    {
+        DelayInfo delay;
+        auto &cls = speed_grade->pip_classes[pip_data(pip).timing_class];
+        delay.min_delay = std::max(0, cls.min_delay);
+        delay.max_delay = std::max(0, cls.max_delay);
+        return delay;
+    }
 
     UpDownhillPipRange getPipsDownhill(WireId wire) const
     {