Add decodePcGen

This commit is contained in:
Dolu1990 2018-03-20 18:34:36 +01:00
parent 1fb138de1f
commit f872d599e2
1 changed files with 49 additions and 90 deletions

View File

@ -160,7 +160,8 @@ class IBusSimplePlugin(interfaceKeepData : Boolean, catchAccessFault : Boolean,
var prefetchExceptionPort : Flow[ExceptionCause] = null var prefetchExceptionPort : Flow[ExceptionCause] = null
def resetVector = BigInt(0x80000000l) def resetVector = BigInt(0x80000000l)
def keepPcPlus4 = false def keepPcPlus4 = false
def decodePcGen = true
def compressedGen = true
lazy val fetcherHalt = False lazy val fetcherHalt = False
lazy val decodeNextPcValid = Bool lazy val decodeNextPcValid = Bool
lazy val decodeNextPc = UInt(32 bits) lazy val decodeNextPc = UInt(32 bits)
@ -191,16 +192,6 @@ class IBusSimplePlugin(interfaceKeepData : Boolean, catchAccessFault : Boolean,
import pipeline.config._ import pipeline.config._
pipeline plug new Area { pipeline plug new Area {
val pcCalc = new Area {
val output = Stream(UInt(32 bits))
//PC calculation without Jump
val pcReg = Reg(UInt(32 bits)) init (resetVector) addAttribute (Verilator.public)
val pcPlus4 = pcReg + 4
if (keepPcPlus4) KeepAttribute(pcPlus4)
when(output.fire) {
pcReg := pcPlus4
}
//JumpService hardware implementation //JumpService hardware implementation
val jump = new Area { val jump = new Area {
@ -214,23 +205,50 @@ class IBusSimplePlugin(interfaceKeepData : Boolean, catchAccessFault : Boolean,
val pcLoad = Flow(UInt(32 bits)) val pcLoad = Flow(UInt(32 bits))
pcLoad.valid := jumpInfos.map(_.interface.valid).orR pcLoad.valid := jumpInfos.map(_.interface.valid).orR
pcLoad.payload := MuxOH(OHMasking.first(valids.asBits), pcs) pcLoad.payload := MuxOH(OHMasking.first(valids.asBits), pcs)
}
def flush = jump.pcLoad.valid
val fetchPc = new Area {
val output = Stream(UInt(32 bits))
//PC calculation without Jump
val pcReg = Reg(UInt(32 bits)) init (resetVector) addAttribute (Verilator.public)
val pcPlus4 = pcReg + 4
if (keepPcPlus4) KeepAttribute(pcPlus4)
when(output.fire) {
pcReg := pcPlus4
}
//application of the selected jump request //application of the selected jump request
when(pcLoad.valid) { when(jump.pcLoad.valid) {
pcReg := pcLoad.payload pcReg := jump.pcLoad.payload
} }
}
output.valid := (RegNext(True) init (False)) // && !jump.pcLoad.valid output.valid := (RegNext(True) init (False)) // && !jump.pcLoad.valid
output.payload := pcReg output.payload := pcReg
} }
def flush = pcCalc.jump.pcLoad.valid val decodePc = ifGen(decodePcGen)(new Area {
//PC calculation without Jump
val pcReg = Reg(UInt(32 bits)) init (resetVector) addAttribute (Verilator.public)
val pcPlus4 = pcReg + 4
if (keepPcPlus4) KeepAttribute(pcPlus4)
when(decode.arbitration.isFiring) {
pcReg := pcPlus4
}
//application of the selected jump request
when(jump.pcLoad.valid) {
pcReg := jump.pcLoad.payload
}
})
val iBusCmd = new Area { val iBusCmd = new Area {
def input = pcCalc.output def input = fetchPc.output
val output = input.continueWhen(iBus.cmd.fire) val output = input.continueWhen(iBus.cmd.fire)
@ -272,16 +290,21 @@ class IBusSimplePlugin(interfaceKeepData : Boolean, catchAccessFault : Boolean,
val injector = new Area { val injector = new Area {
val inputBeforeHalt = iBusRsp.output.s2mPipe(flush) val inputBeforeHalt = iBusRsp.output//.s2mPipe(flush)
val input = inputBeforeHalt.haltWhen(fetcherHalt) val input = inputBeforeHalt.haltWhen(fetcherHalt)
val stage = input.m2sPipe(flush || decode.arbitration.isRemoved) val stage = input.m2sPipe(flush || decode.arbitration.isRemoved)
if(decodePcGen){
decodeNextPcValid := True
decodeNextPc := decodePc.pcReg
}else {
decodeNextPcValid := RegNext(inputBeforeHalt.isStall) decodeNextPcValid := RegNext(inputBeforeHalt.isStall)
decodeNextPc := decode.input(PC) decodeNextPc := decode.input(PC)
}
stage.ready := !decode.arbitration.isStuck stage.ready := !decode.arbitration.isStuck
decode.arbitration.isValid := stage.valid decode.arbitration.isValid := stage.valid
decode.insert(PC) := stage.pc decode.insert(PC) := (if(decodePcGen) decodePc.pcReg else stage.pc)
decode.insert(INSTRUCTION) := stage.rsp.inst decode.insert(INSTRUCTION) := stage.rsp.inst
decode.insert(INSTRUCTION_ANTICIPATED) := Mux(decode.arbitration.isStuck, decode.input(INSTRUCTION), input.rsp.inst) decode.insert(INSTRUCTION_ANTICIPATED) := Mux(decode.arbitration.isStuck, decode.input(INSTRUCTION), input.rsp.inst)
decode.insert(INSTRUCTION_READY) := True decode.insert(INSTRUCTION_READY) := True
@ -295,67 +318,3 @@ class IBusSimplePlugin(interfaceKeepData : Boolean, catchAccessFault : Boolean,
} }
} }
} }
//class IBusSimplePlugin(interfaceKeepData : Boolean, catchAccessFault : Boolean) extends Plugin[VexRiscv]{
// var iBus : IBusSimpleBus = null
//
// object IBUS_ACCESS_ERROR extends Stageable(Bool)
// var decodeExceptionPort : Flow[ExceptionCause] = null
// override def setup(pipeline: VexRiscv): Unit = {
// if(catchAccessFault) {
// val exceptionService = pipeline.service(classOf[ExceptionService])
// decodeExceptionPort = exceptionService.newExceptionPort(pipeline.decode,1)
// }
// }
//
// override def build(pipeline: VexRiscv): Unit = {
// import pipeline._
// import pipeline.config._
// iBus = master(IBusSimpleBus(interfaceKeepData)).setName("iBus")
// prefetch plug new Area {
// val pendingCmd = RegInit(False) clearWhen (iBus.rsp.ready) setWhen (iBus.cmd.fire)
//
// //Emit iBus.cmd request
// iBus.cmd.valid := prefetch.arbitration.isValid && !prefetch.arbitration.removeIt && !prefetch.arbitration.isStuckByOthers && !(pendingCmd && !iBus.rsp.ready) //prefetch.arbitration.isValid && !prefetch.arbitration.isStuckByOthers
// iBus.cmd.pc := prefetch.output(PC)
// prefetch.arbitration.haltItself setWhen (!iBus.cmd.ready || (pendingCmd && !iBus.rsp.ready))
// }
//
// //Bus rsp buffer
// val rspBuffer = if(!interfaceKeepData) new Area{
// val valid = RegInit(False) setWhen(iBus.rsp.ready) clearWhen(!fetch.arbitration.isStuck)
// val error = Reg(Bool)
// val data = Reg(Bits(32 bits))
// when(!valid) {
// data := iBus.rsp.inst
// error := iBus.rsp.error
// }
// } else null
//
// //Insert iBus.rsp into INSTRUCTION
// fetch.insert(INSTRUCTION) := iBus.rsp.inst
// fetch.insert(IBUS_ACCESS_ERROR) := iBus.rsp.error
// if(!interfaceKeepData) {
// when(rspBuffer.valid) {
// fetch.insert(INSTRUCTION) := rspBuffer.data
// fetch.insert(IBUS_ACCESS_ERROR) := rspBuffer.error
// }
// }
//
// fetch.insert(IBUS_ACCESS_ERROR) clearWhen(!fetch.arbitration.isValid) //Avoid interference with instruction injection from the debug plugin
//
// if(interfaceKeepData)
// fetch.arbitration.haltItself setWhen(fetch.arbitration.isValid && !iBus.rsp.ready)
// else
// fetch.arbitration.haltItself setWhen(fetch.arbitration.isValid && !iBus.rsp.ready && !rspBuffer.valid)
//
// decode.insert(INSTRUCTION_ANTICIPATED) := Mux(decode.arbitration.isStuck,decode.input(INSTRUCTION),fetch.output(INSTRUCTION))
// decode.insert(INSTRUCTION_READY) := True
//
// if(catchAccessFault){
// decodeExceptionPort.valid := decode.arbitration.isValid && decode.input(IBUS_ACCESS_ERROR)
// decodeExceptionPort.code := 1
// decodeExceptionPort.badAddr := decode.input(PC)
// }
// }
//}