Add example clocking configs and SingleClockBroadcast option

generators/chipyard/src/main/scala/clocking/ClockBinders.scala

@@ -102,38 +102,28 @@ class WithPassthroughClockGenerator extends OverrideLazyIOBinder({
   }
 })
 
-// Broadcasts a single clock IO to all clock domains
+// Broadcasts a single clock IO to all clock domains. Ignores all requested frequencies
-class WithSingleClockBroadcastClockGenerator extends OverrideLazyIOBinder({
+class WithSingleClockBroadcastClockGenerator(freqMHz: Int = 100) extends OverrideLazyIOBinder({
   (system: HasChipyardPRCI) => {
     implicit val p = GetSystemParameters(system)
-    val implicitClockSinkNode = ClockSinkNode(Seq(ClockSinkParameters(name = Some("implicit_clock"))))
-    system.connectImplicitClockSinkNode(implicitClockSinkNode)
-    InModuleBody {
-      val implicit_clock = implicitClockSinkNode.in.head._1.clock
-      val implicit_reset = implicitClockSinkNode.in.head._1.reset
-      system.asInstanceOf[BaseSubsystem].module match { case l: LazyModuleImp => {
-        l.clock := implicit_clock
-        l.reset := implicit_reset
-      }}
-    }
 
-    val clockGroupsAggregateNode = ClockGroupAggregateNode("single_clock")
+    val clockGroupsAggregator = LazyModule(new ClockGroupAggregator("single_clock"))
     val clockGroupsSourceNode = ClockGroupSourceNode(Seq(ClockGroupSourceParameters()))
-    system.allClockGroupsNode :*= clockGroupsAggregateNode := clockGroupsSourceNode
+    system.chiptopClockGroupsNode :*= clockGroupsAggregator.node := clockGroupsSourceNode
 
     InModuleBody {
-      val clock_wire = Wire(Input(new ClockWithFreq(100)))
+      val clock_wire = Wire(Input(Clock()))
       val reset_wire = Wire(Input(AsyncReset()))
       val (clock_io, clockIOCell) = IOCell.generateIOFromSignal(clock_wire, "clock", p(IOCellKey))
       val (reset_io, resetIOCell) = IOCell.generateIOFromSignal(reset_wire, "reset", p(IOCellKey))
 
       clockGroupsSourceNode.out.foreach { case (bundle, edge) =>
         bundle.member.data.foreach { b =>
-          b.clock := clock_io.clock
+          b.clock := clock_io
           b.reset := reset_io
         }
       }
-      (Seq(clock_io, reset_io), clockIOCell ++ resetIOCell)
+      (Seq(ClockPort(() => clock_io, freqMHz), ResetPort(() => reset_io)), clockIOCell ++ resetIOCell)
     }
   }
 })

generators/chipyard/src/main/scala/config/ClockingConfigs.scala

@@ -0,0 +1,34 @@
+package chipyard
+
+import org.chipsalliance.cde.config.{Config}
+import freechips.rocketchip.diplomacy._
+import freechips.rocketchip.subsystem.{MBUS, SBUS}
+import testchipip.soc.{OBUS}
+
+//==================================================
+// This file contains examples of the different ways
+// clocks can be generated for chiypard designs
+//==================================================
+
+// The default constructs IOs for all requested clocks in the chiptopClockGroupsNode
+// Note: This is what designs inheriting from AbstractConfig do by default
+class DefaultClockingRocketConfig extends Config(
+  new chipyard.clocking.WithPassthroughClockGenerator ++
+  new freechips.rocketchip.subsystem.WithNBigCores(1) ++
+  new chipyard.config.AbstractConfig)
+
+// This is a more physically realistic approach, normally we can't punch out a separate
+// pin for each clock domain. The standard "test chip" approach is to punch a few slow clock
+// inputs, integrate a PLL, and generate an array of selectors/dividers to configure the
+// clocks for each domain. See the source for WithPLLSelectorDividerClockGenerator for more info
+class ChipLikeClockingRocketConfig extends Config(
+  new chipyard.clocking.WithPLLSelectorDividerClockGenerator ++
+  new freechips.rocketchip.subsystem.WithNBigCores(1) ++
+  new chipyard.config.AbstractConfig)
+
+// This merges all the clock domains in chiptopClockGroupsNode into one, then generates a single
+// clock input pin.
+class SingleClockBroadcastRocketConfig extends Config(
+  new chipyard.clocking.WithSingleClockBroadcastClockGenerator ++
+  new freechips.rocketchip.subsystem.WithNBigCores(1) ++
+  new chipyard.config.AbstractConfig)