1
0

64 lines
2.3 KiB
Scala

// See LICENSE.SiFive for license details.
package freechips.rocketchip.amba.axi4
import Chisel._
import chisel3.internal.sourceinfo.SourceInfo
import chisel3.util.IrrevocableIO
import freechips.rocketchip.config.Parameters
import freechips.rocketchip.diplomacy._
import scala.math.{min,max}
// pipe is only used if a queue has depth = 1
class AXI4Buffer(
aw: BufferParams,
w: BufferParams,
b: BufferParams,
ar: BufferParams,
r: BufferParams)(implicit p: Parameters) extends LazyModule
{
def this(aw: BufferParams, br: BufferParams)(implicit p: Parameters) = this(aw, aw, br, aw, br)
def this(x: BufferParams)(implicit p: Parameters) = this(x, x)
def this()(implicit p: Parameters) = this(BufferParams.default)
val node = AXI4AdapterNode(
masterFn = { p => p },
slaveFn = { p => p.copy(minLatency = p.minLatency + min(aw.latency,ar.latency) + min(r.latency,b.latency)) })
lazy val module = new LazyModuleImp(this) {
def buffer[T <: Data](config: BufferParams, data: IrrevocableIO[T]): IrrevocableIO[T] = {
if (config.isDefined) {
Queue.irrevocable(data, config.depth, pipe=config.pipe, flow=config.flow)
} else {
data
}
}
(node.in zip node.out) foreach { case ((in, edgeIn), (out, edgeOut)) =>
out.aw <> buffer(aw, in .aw)
out.w <> buffer(w, in .w)
in .b <> buffer(b, out.b)
out.ar <> buffer(ar, in .ar)
in .r <> buffer(r, out.r)
}
}
}
object AXI4Buffer
{
// applied to the AXI4 source node; y.node := AXI4Buffer(x.node)
def apply() (x: AXI4OutwardNode)(implicit p: Parameters, sourceInfo: SourceInfo): AXI4OutwardNode = apply(BufferParams.default)(x)
def apply(z: BufferParams) (x: AXI4OutwardNode)(implicit p: Parameters, sourceInfo: SourceInfo): AXI4OutwardNode = apply(z, z)(x)
def apply(aw: BufferParams, br: BufferParams)(x: AXI4OutwardNode)(implicit p: Parameters, sourceInfo: SourceInfo): AXI4OutwardNode = apply(aw, aw, br, aw, br)(x)
def apply(
aw: BufferParams,
w: BufferParams,
b: BufferParams,
ar: BufferParams,
r: BufferParams)(x: AXI4OutwardNode)(implicit p: Parameters, sourceInfo: SourceInfo): AXI4OutwardNode = {
val buffer = LazyModule(new AXI4Buffer(aw, w, b, ar, r))
buffer.node :=? x
buffer.node
}
}