Add GenMicro experiment to reduce ice40 area usage.

IBusSimplePlugin now require cmdFork parameters to be set (no default)

src/main/scala/vexriscv/TestsWorkspace.scala

@@ -33,14 +33,14 @@ object TestsWorkspace {
         plugins = List(
           new IBusSimplePlugin(
             resetVector = 0x80000000l,
-            cmdForkOnSecondStage = true,
+            cmdForkOnSecondStage = false,
-            cmdForkPersistence = true,
+            cmdForkPersistence = false,
             prediction = NONE,
             historyRamSizeLog2 = 10,
             catchAccessFault = true,
             compressedGen = false,
             busLatencyMin = 1,
-            injectorStage = true
+            injectorStage = false
           ),
 //          new IBusCachedPlugin(
 //            resetVector = 0x80000000l,

src/main/scala/vexriscv/demo/FormalSimple.scala

@@ -16,6 +16,7 @@ object FormalSimple extends App{
         new IBusSimplePlugin(
           resetVector = 0x00000000l,
           cmdForkOnSecondStage = false,
+          cmdForkPersistence = false,
           prediction = DYNAMIC_TARGET,
           catchAccessFault = false,
           compressedGen = true

src/main/scala/vexriscv/demo/GenCustomCsr.scala

@@ -19,6 +19,7 @@ object GenCustomCsr extends App{
         new IBusSimplePlugin(
           resetVector = 0x00000000l,
           cmdForkOnSecondStage = false,
+          cmdForkPersistence = false,
           prediction = NONE,
           catchAccessFault = false,
           compressedGen = false

src/main/scala/vexriscv/demo/GenCustomSimdAdd.scala

@@ -15,6 +15,7 @@ object GenCustomSimdAdd extends App{
         new IBusSimplePlugin(
           resetVector = 0x00000000l,
           cmdForkOnSecondStage = false,
+          cmdForkPersistence = false,
           prediction = NONE,
           catchAccessFault = false,
           compressedGen = false

src/main/scala/vexriscv/demo/GenDeterministicVex.scala

@@ -14,6 +14,7 @@ object GenDeterministicVex extends App{
         new IBusSimplePlugin(
           resetVector = 0x80000000l,
           cmdForkOnSecondStage = false,
+          cmdForkPersistence = false,
           prediction = STATIC,
           catchAccessFault = true,
           compressedGen = false

src/main/scala/vexriscv/demo/GenFullNoMmuNoCache.scala

@@ -15,6 +15,7 @@ object GenFullNoMmuNoCache extends App{
         new IBusSimplePlugin(
           resetVector = 0x80000000l,
           cmdForkOnSecondStage = false,
+          cmdForkPersistence = false,
           prediction = STATIC,
           catchAccessFault = false,
           compressedGen = false

src/main/scala/vexriscv/demo/GenNoCacheNoMmuMaxPerf.scala

@@ -15,6 +15,7 @@ object GenNoCacheNoMmuMaxPerf extends App{
         new IBusSimplePlugin(
           resetVector = 0x80000000l,
           cmdForkOnSecondStage = false,
+          cmdForkPersistence = false,
           prediction = DYNAMIC_TARGET,
           historyRamSizeLog2 = 8,
           catchAccessFault = true,

src/main/scala/vexriscv/demo/GenSmallAndPerformant.scala

@@ -14,6 +14,7 @@ object GenSmallAndProductive extends App{
         new IBusSimplePlugin(
           resetVector = 0x80000000l,
           cmdForkOnSecondStage = false,
+          cmdForkPersistence = false,
           prediction = NONE,
           catchAccessFault = false,
           compressedGen = false

src/main/scala/vexriscv/demo/GenSmallest.scala

@@ -14,6 +14,7 @@ object GenSmallest extends App{
         new IBusSimplePlugin(
           resetVector = 0x80000000l,
           cmdForkOnSecondStage = false,
+          cmdForkPersistence = false,
           prediction = NONE,
           catchAccessFault = false,
           compressedGen = false

src/main/scala/vexriscv/demo/GenSmallestNoCsr.scala

@@ -19,6 +19,7 @@ object GenSmallestNoCsr extends App{
         new IBusSimplePlugin(
           resetVector = 0x80000000l,
           cmdForkOnSecondStage = false,
+          cmdForkPersistence = false,
           prediction = NONE,
           catchAccessFault = false,
           compressedGen = false

src/main/scala/vexriscv/demo/Murax.scala

@@ -498,6 +498,7 @@ object MuraxDhrystoneReadyMulDivStatic{
       config.cpuPlugins += new IBusSimplePlugin(
         resetVector = 0x80000000l,
         cmdForkOnSecondStage = true,
+        cmdForkPersistence = false,
         prediction = STATIC,
         catchAccessFault = false,
         compressedGen = false

src/main/scala/vexriscv/demo/VexRiscvAvalonForSim.scala

@@ -29,6 +29,7 @@ object VexRiscvAvalonForSim{
           new IBusSimplePlugin(
             resetVector = 0x00000000l,
             cmdForkOnSecondStage = false,
+            cmdForkPersistence = false,
             prediction = STATIC,
             catchAccessFault = false,
             compressedGen = false

src/main/scala/vexriscv/plugin/DBusSimplePlugin.scala

@@ -182,7 +182,10 @@ case class DBusSimpleBus() extends Bundle with IMasterSlave{
 }
 
 
-class DBusSimplePlugin(catchAddressMisaligned : Boolean = false, catchAccessFault : Boolean = false, earlyInjection : Boolean = false/*, idempotentRegions : (UInt) => Bool = (x) => False*/) extends Plugin[VexRiscv]{
+class DBusSimplePlugin(catchAddressMisaligned : Boolean = false,
+                       catchAccessFault : Boolean = false,
+                       earlyInjection : Boolean = false,/*, idempotentRegions : (UInt) => Bool = (x) => False*/
+                       onlyLoadWords : Boolean = false) extends Plugin[VexRiscv]{
 
   var dBus  : DBusSimpleBus = null
 
@@ -220,7 +223,7 @@ class DBusSimplePlugin(catchAddressMisaligned : Boolean = false, catchAccessFaul
 
     decoderService.addDefault(MEMORY_ENABLE, False)
     decoderService.add(
-      List(LB, LH, LW, LBU, LHU, LWU).map(_ -> loadActions) ++
+      (if(onlyLoadWords) List(LW) else List(LB, LH, LW, LBU, LHU, LWU)).map(_ -> loadActions) ++
       List(SB, SH, SW).map(_ -> storeActions)
     )
 
@@ -329,7 +332,7 @@ class DBusSimplePlugin(catchAddressMisaligned : Boolean = false, catchAccessFaul
       )
 
       when(arbitration.isValid && input(MEMORY_ENABLE)) {
-        output(REGFILE_WRITE_DATA) := rspFormated
+        output(REGFILE_WRITE_DATA) := (if(!onlyLoadWords) rspFormated else input(MEMORY_READ_DATA))
       }
 
       if(!earlyInjection)

src/main/scala/vexriscv/plugin/Fetcher.scala

@@ -28,7 +28,7 @@ abstract class IBusFetcherImpl(val catchAccessFault : Boolean,
   var dynamicTargetFailureCorrection : Flow[UInt] = null
   var externalResetVector : UInt = null
   assert(cmdToRspStageCount >= 1)
-  assert(!(cmdToRspStageCount == 1 && !injectorStage))
+//  assert(!(cmdToRspStageCount == 1 && !injectorStage))
   assert(!(compressedGen && !decodePcGen))
   var fetcherHalt : Bool = null
   var fetcherflushIt : Bool = null

src/main/scala/vexriscv/plugin/HazardPessimisticPlugin.scala

@@ -7,6 +7,13 @@ import spinal.lib._
 
 class HazardPessimisticPlugin() extends Plugin[VexRiscv] {
   import Riscv._
+
+  override def setup(pipeline: VexRiscv): Unit = {
+    import pipeline.config._
+    val decoderService = pipeline.service(classOf[DecoderService])
+    decoderService.addDefault(HAS_SIDE_EFFECT, False)
+  }
+
   override def build(pipeline: VexRiscv): Unit = {
     import pipeline._
     import pipeline.config._

src/main/scala/vexriscv/plugin/IBusSimplePlugin.scala

@@ -143,16 +143,17 @@ case class IBusSimpleBus(interfaceKeepData : Boolean) extends Bundle with IMaste
 
 
 class IBusSimplePlugin(resetVector : BigInt,
+                       cmdForkOnSecondStage : Boolean,
+                       cmdForkPersistence : Boolean,
                        catchAccessFault : Boolean = false,
-                       cmdForkOnSecondStage : Boolean = false,
-                       cmdForkPersistence : Boolean = false,
                        prediction : BranchPrediction = NONE,
                        historyRamSizeLog2 : Int = 10,
                        keepPcPlus4 : Boolean = false,
                        compressedGen : Boolean = false,
                        busLatencyMin : Int = 1,
                        pendingMax : Int = 7,
-                       injectorStage : Boolean = true
+                       injectorStage : Boolean = true,
+                       rspHoldValue : Boolean = false
                       ) extends IBusFetcherImpl(
     catchAccessFault = catchAccessFault,
     resetVector = resetVector,
@@ -168,6 +169,7 @@ class IBusSimplePlugin(resetVector : BigInt,
 
   var iBus : IBusSimpleBus = null
   var decodeExceptionPort : Flow[ExceptionCause] = null
+  if(rspHoldValue) assert(busLatencyMin == 1)
 
   override def setup(pipeline: VexRiscv): Unit = {
     super.setup(pipeline)
@@ -221,22 +223,29 @@ class IBusSimplePlugin(resetVector : BigInt,
             discardCounter := (if(cmdForkOnSecondStage) pendingCmdNext else pendingCmd - iBus.rsp.fire.asUInt)
         }
 
-        val rspBuffer = StreamFifoLowLatency(IBusSimpleRsp(), busLatencyMin + (if(cmdForkOnSecondStage && cmdForkPersistence) 1 else 0))
+        val rspBufferOutput = Stream(IBusSimpleRsp())
-        rspBuffer.io.push << iBus.rsp.throwWhen(discardCounter =/= 0).toStream
+
-        rspBuffer.io.flush := flush
+        val rspBuffer = if(!rspHoldValue) new Area{
+          val c = StreamFifoLowLatency(IBusSimpleRsp(), busLatencyMin + (if(cmdForkOnSecondStage && cmdForkPersistence) 1 else 0))
+          c.io.push << iBus.rsp.throwWhen(discardCounter =/= 0).toStream
+          c.io.flush := flush
+          rspBufferOutput << c.io.pop
+        } else new Area{
+          rspBufferOutput << iBus.rsp.throwWhen(discardCounter =/= 0).toStream
+        }
 
         val fetchRsp = FetchRsp()
         fetchRsp.pc := stages.last.output.payload
-        fetchRsp.rsp := rspBuffer.io.pop.payload
+        fetchRsp.rsp := rspBufferOutput.payload
-        fetchRsp.rsp.error.clearWhen(!rspBuffer.io.pop.valid) //Avoid interference with instruction injection from the debug plugin
+        fetchRsp.rsp.error.clearWhen(!rspBufferOutput.valid) //Avoid interference with instruction injection from the debug plugin
 
 
         var issueDetected = False
         val join = Stream(FetchRsp())
-        join.valid := stages.last.output.valid && rspBuffer.io.pop.valid
+        join.valid := stages.last.output.valid && rspBufferOutput.valid
         join.payload := fetchRsp
         stages.last.output.ready := stages.last.output.valid ? join.fire | join.ready
-        rspBuffer.io.pop.ready := join.fire
+        rspBufferOutput.ready := join.fire
         output << join.haltWhen(issueDetected)
 
         if(catchAccessFault){

src/main/scala/vexriscv/plugin/RegFilePlugin.scala

@@ -11,10 +11,14 @@ trait RegFileReadKind
 object ASYNC extends RegFileReadKind
 object SYNC extends RegFileReadKind
 
-class RegFilePlugin(regFileReadyKind : RegFileReadKind,zeroBoot : Boolean = false, writeRfInMemoryStage : Boolean = false) extends Plugin[VexRiscv]{
+class RegFilePlugin(regFileReadyKind : RegFileReadKind,
+                    zeroBoot : Boolean = false,
+                    writeRfInMemoryStage : Boolean = false,
+                    readInExecute : Boolean = false) extends Plugin[VexRiscv]{
   import Riscv._
 
-  assert(!writeRfInMemoryStage)
+//  assert(!writeRfInMemoryStage)
+
 
   override def setup(pipeline: VexRiscv): Unit = {
     import pipeline.config._
@@ -33,19 +37,21 @@ class RegFilePlugin(regFileReadyKind : RegFileReadKind,zeroBoot : Boolean = fals
       if(zeroBoot) regFile.init(List.fill(32)(B(0, 32 bits)))
     }
 
-    //Read register file
-    decode plug new Area{
-      import decode._
-
     //Disable rd0 write in decoding stage
     when(decode.input(INSTRUCTION)(rdRange) === 0) {
       decode.input(REGFILE_WRITE_VALID) := False
     }
 
+    //Read register file
+    val readStage = if(readInExecute) execute else decode
+    readStage plug new Area{
+      import readStage._
+
       //read register file
       val srcInstruction = regFileReadyKind match{
         case `ASYNC` => input(INSTRUCTION)
-        case `SYNC` =>  input(INSTRUCTION_ANTICIPATED)
+        case `SYNC` if !readInExecute =>  input(INSTRUCTION_ANTICIPATED)
+        case `SYNC` if readInExecute =>   Mux(execute.arbitration.isStuck, execute.input(INSTRUCTION), decode.input(INSTRUCTION))
       }
 
       val regFileReadAddress1 = srcInstruction(Riscv.rs1Range).asUInt
@@ -61,8 +67,9 @@ class RegFilePlugin(regFileReadyKind : RegFileReadKind,zeroBoot : Boolean = fals
     }
 
     //Write register file
-    (if(writeRfInMemoryStage) memory else writeBack) plug new Area {
+    val writeStage = if(writeRfInMemoryStage) memory else writeBack
-      import writeBack._
+    writeStage plug new Area {
+      import writeStage._
 
       val regFileWrite = global.regFile.writePort.addAttribute(Verilator.public)
       regFileWrite.valid := output(REGFILE_WRITE_VALID) && arbitration.isFiring

src/test/scala/vexriscv/experimental/GenMicro.scala

@@ -0,0 +1,113 @@
+package vexriscv.experimental
+
+import spinal.core._
+import spinal.lib.eda.bench.{AlteraStdTargets, Bench, Rtl, XilinxStdTargets}
+import spinal.lib.eda.icestorm.IcestormStdTargets
+import vexriscv.demo.{GenSmallestNoCsr, Murax, MuraxConfig}
+import vexriscv.plugin._
+import vexriscv.{VexRiscv, VexRiscvConfig, plugin}
+
+/**
+ * Created by spinalvm on 15.06.17.
+ */
+object GenMicro extends App{
+  def cpu() = {
+    val removeOneFetchStage = true
+    val writeBackOpt = true
+    val onlyLoadWords = true
+    val rspHoldValue = true
+    val earlyBranch = false
+    val noShifter = true
+    val pessimisticHazard = true
+    new VexRiscv(
+      config = VexRiscvConfig(
+        plugins = List(
+          //        new PcManagerSimplePlugin(
+          //          resetVector = 0x00000000l,
+          //          relaxedPcCalculation = false
+          //        ),
+
+          new IBusSimplePlugin(
+            resetVector = 0x80000000l,
+            cmdForkOnSecondStage = false,
+            cmdForkPersistence = false,
+            prediction = NONE,
+            catchAccessFault = false,
+            compressedGen = false,
+            injectorStage = !removeOneFetchStage,
+            rspHoldValue = rspHoldValue
+          ),
+          new DBusSimplePlugin(
+            catchAddressMisaligned = false,
+            catchAccessFault = false,
+            earlyInjection = writeBackOpt,
+            onlyLoadWords = onlyLoadWords
+          ),
+          new DecoderSimplePlugin(
+            catchIllegalInstruction = false
+          ),
+          new RegFilePlugin(
+            regFileReadyKind = plugin.SYNC,
+            zeroBoot = false,
+            readInExecute = removeOneFetchStage,
+            writeRfInMemoryStage = writeBackOpt
+          ),
+          new IntAluPlugin,
+          new SrcPlugin(
+            separatedAddSub = false,
+            executeInsertion = removeOneFetchStage
+          ),
+          if(!pessimisticHazard)
+            new HazardSimplePlugin(
+              bypassExecute = false,
+              bypassMemory = false,
+              bypassWriteBack = false,
+              bypassWriteBackBuffer = false,
+              pessimisticUseSrc = false,
+              pessimisticWriteRegFile = false,
+              pessimisticAddressMatch = false
+            )
+          else
+            new HazardPessimisticPlugin(),
+          new BranchPlugin(
+            earlyBranch = earlyBranch,
+            catchAddressMisaligned = false
+          ),
+          new YamlPlugin("cpu0.yaml")
+        ) ++ (if(noShifter) Nil else List(new LightShifterPlugin))
+      )
+    )
+  }
+  SpinalConfig(mergeAsyncProcess = false).generateVerilog(cpu())
+}
+
+
+
+object GenMicroSynthesis {
+  def main(args: Array[String]) {
+    val microNoCsr = new Rtl {
+      override def getName(): String = "MicroNoCsr"
+      override def getRtlPath(): String = "MicroNoCsr.v"
+      SpinalVerilog(GenMicro.cpu().setDefinitionName(getRtlPath().split("\\.").head))
+    }
+
+    val smallestNoCsr = new Rtl {
+      override def getName(): String = "SmallestNoCsr"
+      override def getRtlPath(): String = "SmallestNoCsr.v"
+      SpinalVerilog(GenSmallestNoCsr.cpu().setDefinitionName(getRtlPath().split("\\.").head))
+    }
+
+    val rtls = List(microNoCsr)
+//    val rtls = List(smallestNoCsr)
+
+    val targets = IcestormStdTargets().take(1) ++ XilinxStdTargets(
+      vivadoArtix7Path = "/eda/Xilinx/Vivado/2017.2/bin"
+    ) ++ AlteraStdTargets(
+      quartusCycloneIVPath = "/eda/intelFPGA_lite/17.0/quartus/bin/",
+      quartusCycloneVPath  = "/eda/intelFPGA_lite/17.0/quartus/bin/"
+    )
+
+
+    Bench(rtls, targets, "/eda/tmp/")
+  }
+}

src/test/scala/vexriscv/experimental/config.scala

@@ -12,7 +12,7 @@ object Presentation extends App{
   val config = VexRiscvConfig()
 
   config.plugins ++= List(
-    new IBusSimplePlugin(resetVector = 0x80000000l),
+//    new IBusSimplePlugin(resetVector = 0x80000000l),
     new DBusSimplePlugin,
     new CsrPlugin(CsrPluginConfig.smallest),
     new DecoderSimplePlugin,