Initial Commit

1 files changed, 24 insertions, 0 deletions

diff --git a/VexRiscv/src/main/scala/vexriscv/plugin/HazardPessimisticPlugin.scala b/VexRiscv/src/main/scala/vexriscv/plugin/HazardPessimisticPlugin.scala
new file mode 100644
index 0000000..5a8f4d3
--- /dev/null
+++ b/VexRiscv/src/main/scala/vexriscv/plugin/HazardPessimisticPlugin.scala
@@ -0,0 +1,24 @@
+package vexriscv.plugin
+
+import vexriscv._
+import spinal.core._
+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._
+
+    val writesInPipeline = stages.dropWhile(_ != execute).map(s => s.arbitration.isValid && s.input(REGFILE_WRITE_VALID)) :+ RegNext(stages.last.arbitration.isValid && stages.last.input(REGFILE_WRITE_VALID))
+    decode.arbitration.haltByOther.setWhen(decode.arbitration.isValid && writesInPipeline.orR)
+  }
+}