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rocket-chip/src/main/scala/coreplex/PeripheryBus.scala
Wesley W. Terpstra b8098d18be
diplomacy: remove the :=? operator in favour of magic :*=* (#1139)
The reason for the :=? operator was for when you have an adapter chain
whose direction of cardinality you could not know. We used explicit
directives to tell these compositions which way to go.

Unfortunately, that makes the API leaky. You think the chain of adapters
is just one adapter, but you have to use strange Cardinality scopes to
use it. That's just bad.

The new :*=* just automagically figures it out from the graph.
2017-12-01 18:28:37 -08:00

62 lines
1.9 KiB
Scala

// See LICENSE.SiFive for license details.
package freechips.rocketchip.coreplex
import Chisel._
import freechips.rocketchip.config.{Field, Parameters}
import freechips.rocketchip.diplomacy._
import freechips.rocketchip.tilelink._
import freechips.rocketchip.config.Field
case class PeripheryBusParams(
beatBytes: Int,
blockBytes: Int,
masterBuffering: BufferParams = BufferParams.default,
slaveBuffering: BufferParams = BufferParams.none,
arithmetic: Boolean = true,
frequency: BigInt = BigInt(100000000) // 100 MHz as default bus frequency
) extends TLBusParams {
}
case object PeripheryBusKey extends Field[PeripheryBusParams]
class PeripheryBus(params: PeripheryBusParams)(implicit p: Parameters) extends TLBusWrapper(params, "PeripheryBus") {
def toFixedWidthSingleBeatSlave(widthBytes: Int) = {
TLFragmenter(widthBytes, params.blockBytes) := outwardWWNode
}
def toLargeBurstSlave(maxXferBytes: Int) = {
TLFragmenter(params.beatBytes, maxXferBytes) := outwardBufNode
}
val fromSystemBus: TLInwardNode = {
val atomics = LazyModule(new TLAtomicAutomata(arithmetic = params.arithmetic))
xbar.node :*= TLBuffer(params.masterBuffering) :*= atomics.node
}
def toTile(name: Option[String] = None)(gen: Parameters => TLInwardNode) {
this {
LazyScope(s"${busName}ToTile${name.getOrElse("")}") {
FlipRendering { implicit p =>
gen(p) :*= outwardNode
}
}
}
}
}
/** Provides buses that serve as attachment points,
* for use in traits that connect individual devices or external ports.
*/
trait HasPeripheryBus extends HasSystemBus {
private val pbusParams = p(PeripheryBusKey)
val pbusBeatBytes = pbusParams.beatBytes
val pbus = LazyModule(new PeripheryBus(pbusParams))
// The peripheryBus hangs off of systemBus; here we convert TL-UH -> TL-UL
pbus.fromSystemBus :*= sbus.toPeripheryBus()
}