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Merge pull request #533 from ucb-bar/rational-crossing

Rational clock crossing
This commit is contained in:
Wesley W. Terpstra 2017-01-26 22:30:04 -08:00 committed by GitHub
commit 19c58630d2
7 changed files with 336 additions and 4 deletions

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@ -137,7 +137,7 @@ class TLAsyncCrossing(depth: Int = 8, sync: Int = 3)(implicit p: Parameters) ext
/** Synthesizeable unit tests */
import unittest._
class TLRAMCrossing(implicit p: Parameters) extends LazyModule {
class TLRAMAsyncCrossing(implicit p: Parameters) extends LazyModule {
val model = LazyModule(new TLRAMModel)
val ram = LazyModule(new TLRAM(AddressSet(0x0, 0x3ff)))
val fuzz = LazyModule(new TLFuzzer(5000))
@ -168,6 +168,6 @@ class TLRAMCrossing(implicit p: Parameters) extends LazyModule {
}
}
class TLRAMCrossingTest(implicit p: Parameters) extends UnitTest(timeout = 500000) {
io.finished := Module(LazyModule(new TLRAMCrossing).module).io.finished
class TLRAMAsyncCrossingTest(implicit p: Parameters) extends UnitTest(timeout = 500000) {
io.finished := Module(LazyModule(new TLRAMAsyncCrossing).module).io.finished
}

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@ -251,3 +251,12 @@ class TLAsyncBundle(params: TLAsyncBundleParameters) extends TLAsyncBundleBase(p
val d = new AsyncBundle(params.depth, new TLBundleD(params.base)).flip
val e = new AsyncBundle(params.depth, new TLBundleE(params.base))
}
class TLRationalBundle(params: TLBundleParameters) extends TLBundleBase(params)
{
val a = RationalIO(new TLBundleA(params))
val b = RationalIO(new TLBundleB(params)).flip
val c = RationalIO(new TLBundleC(params))
val d = RationalIO(new TLBundleD(params)).flip
val e = RationalIO(new TLBundleE(params))
}

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@ -180,3 +180,39 @@ case class TLAsyncSinkNode(depth: Int, sync: Int) extends MixedNode(TLAsyncImp,
uFn = { case (1, Seq(p)) => Seq(TLAsyncManagerPortParameters(depth, p)) },
numPO = 1 to 1,
numPI = 1 to 1)
object TLRationalImp extends NodeImp[TLClientPortParameters, TLManagerPortParameters, TLEdgeParameters, TLEdgeParameters, TLRationalBundle]
{
def edgeO(pd: TLClientPortParameters, pu: TLManagerPortParameters): TLEdgeParameters = TLEdgeParameters(pd, pu)
def edgeI(pd: TLClientPortParameters, pu: TLManagerPortParameters): TLEdgeParameters = TLEdgeParameters(pd, pu)
def bundleO(eo: Seq[TLEdgeParameters]): Vec[TLRationalBundle] = Vec(eo.size, new TLRationalBundle(TLBundleParameters.union(eo.map(_.bundle))))
def bundleI(ei: Seq[TLEdgeParameters]): Vec[TLRationalBundle] = Vec(ei.size, new TLRationalBundle(TLBundleParameters.union(ei.map(_.bundle))))
def colour = "#00ff00" // green
def connect(bo: => TLRationalBundle, bi: => TLRationalBundle, ei: => TLEdgeParameters)(implicit p: Parameters, sourceInfo: SourceInfo): (Option[LazyModule], () => Unit) = {
(None, () => { bi <> bo })
}
override def mixO(pd: TLClientPortParameters, node: OutwardNode[TLClientPortParameters, TLManagerPortParameters, TLRationalBundle]): TLClientPortParameters =
pd.copy(clients = pd.clients.map { c => c.copy (nodePath = node +: c.nodePath) })
override def mixI(pu: TLManagerPortParameters, node: InwardNode[TLClientPortParameters, TLManagerPortParameters, TLRationalBundle]): TLManagerPortParameters =
pu.copy(managers = pu.managers.map { m => m.copy (nodePath = node +: m.nodePath) })
}
case class TLRationalIdentityNode() extends IdentityNode(TLRationalImp)
case class TLRationalOutputNode() extends OutputNode(TLRationalImp)
case class TLRationalInputNode() extends InputNode(TLRationalImp)
case class TLRationalSourceNode() extends MixedNode(TLImp, TLRationalImp)(
dFn = { case (_, s) => s },
uFn = { case (_, s) => s.map(p => p.copy(minLatency = 1)) }, // discard cycles from other clock domain
numPO = 0 to 999,
numPI = 0 to 999)
case class TLRationalSinkNode() extends MixedNode(TLRationalImp, TLImp)(
dFn = { case (_, s) => s.map(p => p.copy(minLatency = 1)) },
uFn = { case (_, s) => s },
numPO = 0 to 999,
numPI = 0 to 999)

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@ -0,0 +1,184 @@
// See LICENSE.SiFive for license details.
// If you know two clocks are related with a N:1 or 1:N relationship, you
// can cross the clock domains with lower latency than an AsyncQueue.
// This clock crossing behaves almost identically to a TLBuffer(2):
// - It adds one cycle latency to each clock domain.
// - All outputs of TLRational are registers (bits, valid, and ready).
// - It costs 3*bits registers as opposed to 2*bits in a TLBuffer(2)
package uncore.tilelink2
import Chisel._
import chisel3.internal.sourceinfo.SourceInfo
import config._
import diplomacy._
import util._
class TLRationalCrossingSource(implicit p: Parameters) extends LazyModule
{
val node = TLRationalSourceNode()
lazy val module = new LazyModuleImp(this) {
val io = new Bundle {
val in = node.bundleIn
val out = node.bundleOut
}
((io.in zip io.out) zip (node.edgesIn zip node.edgesOut)) foreach { case ((in, out), (edgeIn, edgeOut)) =>
val bce = edgeIn.manager.anySupportAcquireB && edgeIn.client.anySupportProbe
out.a <> ToRational(in.a)
in.d <> FromRational(out.d)
if (bce) {
in.b <> FromRational(out.b)
out.c <> ToRational(in.c)
out.e <> ToRational(in.e)
} else {
in.b.valid := Bool(false)
in.c.ready := Bool(true)
in.e.ready := Bool(true)
out.b.ready := Bool(true)
out.c.valid := Bool(false)
out.e.valid := Bool(false)
out.b.sink := UInt(0)
out.c.source := UInt(0)
out.e.source := UInt(0)
}
}
}
}
class TLRationalCrossingSink(implicit p: Parameters) extends LazyModule
{
val node = TLRationalSinkNode()
lazy val module = new LazyModuleImp(this) {
val io = new Bundle {
val in = node.bundleIn
val out = node.bundleOut
}
((io.in zip io.out) zip (node.edgesIn zip node.edgesOut)) foreach { case ((in, out), (edgeIn, edgeOut)) =>
val bce = edgeOut.manager.anySupportAcquireB && edgeOut.client.anySupportProbe
out.a <> FromRational(in.a)
in.d <> ToRational(out.d)
if (bce) {
in.b <> ToRational(out.b)
out.c <> FromRational(in.c)
out.e <> FromRational(in.e)
} else {
out.b.ready := Bool(true)
out.c.valid := Bool(false)
out.e.valid := Bool(false)
in.b.valid := Bool(false)
in.c.ready := Bool(true)
in.e.ready := Bool(true)
in.b.source := UInt(0)
in.c.sink := UInt(0)
in.e.sink := UInt(0)
}
}
}
}
object TLRationalCrossingSource
{
// applied to the TL source node; y.node := TLRationalCrossingSource()(x.node)
def apply()(x: TLOutwardNode)(implicit p: Parameters, sourceInfo: SourceInfo): TLRationalOutwardNode = {
val source = LazyModule(new TLRationalCrossingSource)
source.node := x
source.node
}
}
object TLRationalCrossingSink
{
// applied to the TL source node; y.node := TLRationalCrossingSink()(x.node)
def apply()(x: TLRationalOutwardNode)(implicit p: Parameters, sourceInfo: SourceInfo): TLOutwardNode = {
val sink = LazyModule(new TLRationalCrossingSink)
sink.node := x
sink.node
}
}
class TLRationalCrossing(implicit p: Parameters) extends LazyModule
{
val nodeIn = TLInputNode()
val nodeOut = TLOutputNode()
val node = NodeHandle(nodeIn, nodeOut)
val source = LazyModule(new TLRationalCrossingSource)
val sink = LazyModule(new TLRationalCrossingSink)
val _ = (sink.node := source.node) // no monitor
val in = (source.node := nodeIn)
val out = (nodeOut := sink.node)
lazy val module = new LazyModuleImp(this) {
val io = new Bundle {
val in = nodeIn.bundleIn
val in_clock = Clock(INPUT)
val in_reset = Bool(INPUT)
val out = nodeOut.bundleOut
val out_clock = Clock(INPUT)
val out_reset = Bool(INPUT)
}
source.module.clock := io.in_clock
source.module.reset := io.in_reset
in.foreach { lm =>
lm.module.clock := io.in_clock
lm.module.reset := io.in_reset
}
sink.module.clock := io.out_clock
sink.module.reset := io.out_reset
out.foreach { lm =>
lm.module.clock := io.out_clock
lm.module.reset := io.out_reset
}
}
}
/** Synthesizeable unit tests */
import unittest._
class TLRAMRationalCrossing(implicit p: Parameters) extends LazyModule {
val fuzz = LazyModule(new TLFuzzer(5000))
val model = LazyModule(new TLRAMModel)
val cross = LazyModule(new TLRationalCrossing)
val delay = LazyModule(new TLDelayer(0.25))
val ram = LazyModule(new TLRAM(AddressSet(0x0, 0x3ff)))
model.node := fuzz.node
cross.node := TLDelayer(0.25)(TLFragmenter(4, 256)(model.node))
val monitor1 = (delay.node := cross.node)
val monitor2 = (ram.node := delay.node)
val monitors = monitor1.toList ++ monitor2.toList
lazy val module = new LazyModuleImp(this) with HasUnitTestIO {
io.finished := fuzz.module.io.finished
// Shove the RAM into another clock domain
val clocks = Module(new util.Pow2ClockDivider(2))
ram.module.clock := clocks.io.clock_out
delay.module.clock := clocks.io.clock_out
// ... and safely cross TL2 into it
cross.module.io.in_clock := clock
cross.module.io.in_reset := reset
cross.module.io.out_clock := clocks.io.clock_out
cross.module.io.out_reset := reset
// Push the Monitors into the right clock domain
monitors.foreach { m => m.module.clock := clocks.io.clock_out }
}
}
class TLRAMRationalCrossingTest(implicit p: Parameters) extends UnitTest(timeout = 500000) {
io.finished := Module(LazyModule(new TLRAMRationalCrossing).module).io.finished
}

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@ -10,6 +10,7 @@ package object tilelink2
type TLInwardNode = InwardNodeHandle[TLClientPortParameters, TLManagerPortParameters, TLBundle]
type TLOutwardNode = OutwardNodeHandle[TLClientPortParameters, TLManagerPortParameters, TLBundle]
type TLAsyncOutwardNode = OutwardNodeHandle[TLAsyncClientPortParameters, TLAsyncManagerPortParameters, TLAsyncBundle]
type TLRationalOutwardNode = OutwardNodeHandle[TLClientPortParameters, TLManagerPortParameters, TLRationalBundle]
type IntOutwardNode = OutwardNodeHandle[IntSourcePortParameters, IntSinkPortParameters, Vec[Bool]]
def OH1ToOH(x: UInt) = (x << 1 | UInt(1)) & ~Cat(UInt(0, width=1), x)

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@ -30,7 +30,8 @@ class WithTLSimpleUnitTests extends Config((site, here, up) => {
Module(new uncore.tilelink2.TLRAMSimpleTest(16)),
Module(new uncore.tilelink2.TLRR0Test),
Module(new uncore.tilelink2.TLRR1Test),
Module(new uncore.tilelink2.TLRAMCrossingTest) ) }
Module(new uncore.tilelink2.TLRAMRationalCrossingTest),
Module(new uncore.tilelink2.TLRAMAsyncCrossingTest) ) }
})
class WithTLWidthUnitTests extends Config((site, here, up) => {

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@ -0,0 +1,101 @@
// See LICENSE.SiFive for license details.
// If you know two clocks are related with a N:1 or 1:N relationship, you
// can cross the clock domains with lower latency than an AsyncQueue. This
// crossing adds 1 cycle in the target clock domain.
package util
import Chisel._
final class RationalIO[T <: Data](gen: T) extends Bundle
{
val bits = gen.chiselCloneType
val valid = Bool()
val source = UInt(width = 2)
val ready = Bool().flip
val sink = UInt(width = 2).flip
override def cloneType: this.type = new RationalIO(gen).asInstanceOf[this.type]
}
object RationalIO
{
def apply[T <: Data](gen: T) = new RationalIO(gen)
}
class RationalCrossingSource[T <: Data](gen: T) extends Module
{
val io = new Bundle {
val enq = DecoupledIO(gen).flip
val deq = RationalIO(gen)
}
val enq = Queue(io.enq, 1, flow=true)
val deq = io.deq
val count = RegInit(UInt(0, width = 2))
val equal = count === deq.sink
deq.valid := enq.valid
deq.source := count
deq.bits := Mux(equal, enq.bits, RegEnable(enq.bits, equal))
enq.ready := Mux(equal, deq.ready, count(1) =/= deq.sink(0))
when (enq.fire()) { count := Cat(count(0), !count(1)) }
}
class RationalCrossingSink[T <: Data](gen: T) extends Module
{
val io = new Bundle {
val enq = RationalIO(gen).flip
val deq = DecoupledIO(gen)
}
val enq = io.enq
val deq = Wire(io.deq)
io.deq <> Queue(deq, 1, pipe=true)
val count = RegInit(UInt(0, width = 2))
val equal = count === enq.source
enq.ready := deq.ready
enq.sink := count
deq.bits := enq.bits
deq.valid := Mux(equal, enq.valid, count(1) =/= enq.source(0))
when (deq.fire()) { count := Cat(count(0), !count(1)) }
}
class RationalCrossing[T <: Data](gen: T) extends Module
{
val io = new CrossingIO(gen)
val source = Module(new RationalCrossingSource(gen))
val sink = Module(new RationalCrossingSink(gen))
source.clock := io.enq_clock
source.reset := io.enq_reset
sink .clock := io.deq_clock
sink .reset := io.deq_reset
source.io.enq <> io.enq
io.deq <> sink.io.deq
}
object ToRational
{
def apply[T <: Data](x: DecoupledIO[T]): RationalIO[T] = {
val source = Module(new RationalCrossingSource(x.bits))
source.io.enq <> x
source.io.deq
}
}
object FromRational
{
def apply[T <: Data](x: RationalIO[T]): DecoupledIO[T] = {
val sink = Module(new RationalCrossingSink(x.bits))
sink.io.enq <> x
sink.io.deq
}
}