Traits

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Traits

Diplomacy automatically runs when the outer constructor runs.

Any class that has a TileLink connection, do new <inner> inside the outer class

Ex: in the outer class, create new instance of xBarInner (although, in rocket the inner ends in "Imp" instead of "Inner"

For the inner, it can see the val in the outer, and ??? <== MISSING

Note that the outer class is lazy, and the inner class is also lazy, but a special kind of lazy called LazyImp -- not clear the difference.

package freechips.rocketchip.subsystem
import Chisel._
import freechips.rocketchip.config.{Field, Parameters}
import freechips.rocketchip.diplomacy._
import freechips.rocketchip.tilelink._

class TLaddr extends Bundle {
  val addr        = UInt(39.W) // 39 phys addr bits
}
class TLdata extends Bundle {
  val data        = UInt(64.W) // 64b TL interface  
}
class tile_blackbox extends BlackBox {
 val io = IO(new Bundle { // using scala's anonymous class syntax
    val tile_a_chan = Decoupled(new TLaddr)
    val tile_d_chan = Decoupled(new TLdata)      
})}

// You can expose a lot of tilelink ports like (peripheral bus, system bus, various crossbars 
// that are instantiated inside BaseSubsystem) by extending basesubsystem of rocket-chip, 
// then using the same names to wire your own chisel modules to them.

trait HasExample1TileOuter{ this: BaseSubsystem =>
  private val portName = "example-tilelink"
  val exampleInstance = LazyModule(new ExampleTileModule)

  val managernode = locateTLBusWrapper(FBUS) //helper scala fn in rocket-chip repo 
  // FBUS is defined as a val in another file in same package (subsystem pkg)
  // the call returns a TL node (an outer) that is part of FBUS
  managernode.fromPort(Some(portName))() :=* exampleInstance.dmanode0

  }

trait HasExampleTileInner extends LazyModuleImp {
  val outer: HasExampleTileOuter
}

//This is the outer class
class ExampleTileModule(implicit p: Parameters) extends LazyModule {

    val device = new SimpleDevice("DTname", Seq("IntenSivate"))

    //TLClientNode 
    val exampleNode0 = TLClientNode(Seq(TLClientPortParameters(
        Seq(TLClientParameters(
            name = "YourTilelinkModulename",
            sourceId = IdRange(0, 1))))))
 
    lazy val module = new ExampleTileModuleImp(this)

}

//This is the inner class
// Actual Device RTL
class ExampleTileModuleImp (outer: ExampleTileModule) extends LazyModuleImp(outer) {
    val (tl0, edge0) = outer.dmanode0.out(0)
    val addrBits0 = edge0.bundle.addressBits
    val beatBytes = (edge0.bundle.dataBits / 8)

    val blackbox_inst = Module(new tile_blackbox)
    tl0.a <> blackbox_inst.io.tile_a_chan
    tl0.d <> blackbox_inst.io.tile_d_chan

}

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