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AXI4Xbar: reduce number of special cases

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This commit is contained in:
Wesley W. Terpstra 2017-11-14 13:23:12 -08:00
parent 9004ecdf25
commit e370934c50
1 changed files with 4 additions and 9 deletions
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13
src/main/scala/amba/axi4/Xbar.scala
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@ -96,15 +96,8 @@ class AXI4Xbar(
for (master <- edgesIn(i).master.masters) { for (master <- edgesIn(i).master.masters) {
def idTracker(port: UInt, req_fire: Bool, resp_fire: Bool) = { def idTracker(port: UInt, req_fire: Bool, resp_fire: Bool) = {
if (master.maxFlight == Some(1)) { if (master.maxFlight == Some(0)) {
// No need to worry about response order if at most 1 request possible
Bool(true) Bool(true)
} else if (maxFlightPerId == 1) {
// No need to track where it went if we cap it at 1 request
val allow = RegInit(Bool(true))
when (req_fire) { allow := Bool(false) }
when (resp_fire) { allow := Bool(true) }
allow
} else { } else {
val legalFlight = master.maxFlight.getOrElse(maxFlightPerId+1) val legalFlight = master.maxFlight.getOrElse(maxFlightPerId+1)
val flight = legalFlight min maxFlightPerId val flight = legalFlight min maxFlightPerId
@ -115,7 +108,9 @@ class AXI4Xbar(
assert (!resp_fire || count =/= UInt(0)) assert (!resp_fire || count =/= UInt(0))
assert (!req_fire || count =/= UInt(flight)) assert (!req_fire || count =/= UInt(flight))
when (req_fire) { last := port } when (req_fire) { last := port }
(count === UInt(0) || last === port) && (Bool(!canOverflow) || count =/= UInt(flight)) // No need to track where it went if we cap it at 1 request
val portMatch = if (flight == 1) { Bool(true) } else { last === port }
(count === UInt(0) || portMatch) && (Bool(!canOverflow) || count =/= UInt(flight))
} }
} }