diff --git a/src/main/scala/backBoard/shin/Interface.scala b/src/main/scala/backBoard/shin/Interface.scala
index 2346c35..a592a9a 100644
--- a/src/main/scala/backBoard/shin/Interface.scala
+++ b/src/main/scala/backBoard/shin/Interface.scala
@@ -813,7 +813,7 @@ with InterfaceSystem
   io.txReq.bits.txSM  := mReg.txSM
   io.txReq.bits.rxSM  := mReg.rxSM
   // io.txReq.bits.txLength := //mReg.txLength
-  io.txReq.valid := isEnW & addrw === "h20".U & dataw.extract(0) === "b1".U //& mReg.txLength =/= 0.U
+  io.txReq.valid := RegNext(isEnW & addrw === "h20".U & dataw.extract(0) === "b1".U, false.B) //& mReg.txLength =/= 0.U
 
 
 
diff --git a/src/main/scala/backBoard/shin/SlaveParser.scala b/src/main/scala/backBoard/shin/SlaveParser.scala
index d9964f8..ef99210 100644
--- a/src/main/scala/backBoard/shin/SlaveParser.scala
+++ b/src/main/scala/backBoard/shin/SlaveParser.scala
@@ -716,7 +716,9 @@ trait SlaveParserProbe{ this: SlaveParserBase =>
 
   when( downRecParser.io.frameReq.fire & downRecParser.io.frameReq.bits.frameStyle === FRAME_STYLE_PROBE ){ //下行来了一个嗅探包
     isReadyToProbe := true.B
-    assert( downSendGen.io.stateCurr === STATE_IDLE )
+    when( downSendGen.io.stateCurr =/= STATE_IDLE ){
+      printf("Error! downSendGen is busy while a Probe-Frame arrival!\n")
+    }
   } .elsewhen( upRecParser.io.frameReq.fire & upRecParser.io.frameReq.bits.frameStyle === FRAME_STYLE_PROBE ){ //上行来了一个嗅探包
     isReadyToProbe := false.B
   } .elsewhen( isWatchDogOverflow ){