Files
chipyard/generators/example/src/main/scala/GCDMMIOBlackBox.scala
2019-09-26 01:47:31 -07:00

99 lines
2.8 KiB
Scala

package example
import chisel3._
import chisel3.util._
import chisel3.core.{IntParam, Reset}
import freechips.rocketchip.amba.axi4._
import freechips.rocketchip.subsystem.BaseSubsystem
import freechips.rocketchip.config.{Parameters, Field}
import freechips.rocketchip.diplomacy._
import freechips.rocketchip.regmapper.{HasRegMap, RegField}
import freechips.rocketchip.tilelink._
import freechips.rocketchip.util.UIntIsOneOf
// DOC include start: GCD blackbox
class GCDMMIOBlackBox(w: Int) extends BlackBox(Map("WIDTH" -> IntParam(w))) with HasBlackBoxResource {
val io = IO(new Bundle {
val clock = Input(Clock())
val reset = Input(Bool())
val input_ready = Output(Bool())
val input_valid = Input(Bool())
val x = Input(UInt(w.W))
val y = Input(UInt(w.W))
val output_ready = Input(Bool())
val output_valid = Output(Bool())
val gcd = Output(UInt(w.W))
})
addResource("/vsrc/GCDMMIOBlackBox.v")
}
// DOC include end: GCD blackbox
// DOC include start: GCD instance regmap
case class GCDParams(address: BigInt, beatBytes: Int, width: Int)
trait GCDModule extends HasRegMap {
implicit val p: Parameters
def params: GCDParams
val clock: Clock
val reset: Reset
val impl = Module(new GCDMMIOBlackBox(params.width))
// How many clock cycles in a PWM cycle?
val x = Reg(UInt(params.width.W))
val y = Wire(new DecoupledIO(impl.io.y))
val gcd = Wire(new DecoupledIO(impl.io.gcd))
val status = Cat(impl.io.input_ready, impl.io.output_valid)
impl.io.clock := clock
impl.io.reset := reset.asBool
impl.io.x := x
impl.io.y := y.bits
impl.io.input_valid := y.valid
y.ready := impl.io.input_ready
gcd.bits := impl.io.gcd
gcd.valid := impl.io.output_valid
impl.io.output_ready := gcd.ready
regmap(
0x00 -> Seq(
RegField.r(2, status)), // a read-only register capturing current status
0x04 -> Seq(
RegField.w(params.width, x)), // a plain, write-only register
0x08 -> Seq(
RegField.w(params.width, y)), // write-only, y.valid is set on write
0x0C -> Seq(
RegField.r(params.width, gcd))) // read-only, gcd.ready is set on read
}
// DOC include end: GCD instance regmap
// DOC include start: GCD cake
class GCD(c: GCDParams)(implicit p: Parameters)
extends TLRegisterRouter(
c.address, "gcd", Seq("ucbbar,gcd"),
beatBytes = c.beatBytes)(
new TLRegBundle(c, _))(
new TLRegModule(c, _, _) with GCDModule)
trait HasPeripheryGCD { this: BaseSubsystem =>
implicit val p: Parameters
private val address = 0x2000
private val portName = "gcd"
private val gcdWidth = 32
val gcd = LazyModule(new GCD(
GCDParams(address, pbus.beatBytes, gcdWidth))(p))
pbus.toVariableWidthSlave(Some(portName)) { gcd.node }
}
trait HasPeripheryGCDModuleImp extends LazyModuleImp {
implicit val p: Parameters
val outer: HasPeripheryGCD
}
// DOC include end: GCD cake