From 4a0b14f07ed51adbe9bd4fafc8024a04e7165180 Mon Sep 17 00:00:00 2001
From: Yangyang Zhu <68588633+DavidZyy@users.noreply.github.com>
Date: Thu, 28 Dec 2023 22:37:16 +0800
Subject: [PATCH] Update Crossbar.scala

Fix potential bugs that make io.in.resp.valid only valid in s_resp state.
outSelRespVec is one beat slower than outSelVec, if the chosen slave in outSelRespVec return valid in one cycle, and the outSelVec           is another slave, it will return the false result to master.
And only ready to receive request at s_idle state make the logic more clear.
---
 src/main/scala/bus/simplebus/Crossbar.scala | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/main/scala/bus/simplebus/Crossbar.scala b/src/main/scala/bus/simplebus/Crossbar.scala
index 815d8885..4d1a3366 100644
--- a/src/main/scala/bus/simplebus/Crossbar.scala
+++ b/src/main/scala/bus/simplebus/Crossbar.scala
@@ -58,7 +58,7 @@ class SimpleBusCrossbar1toN(addressSpace: List[(Long, Long)]) extends Module {
   }
 
   // bind out.req channel
-  io.in.req.ready := Mux1H(outSelVec, io.out.map(_.req.ready)) || reqInvalidAddr
+  io.in.req.ready := Mux1H(outSelVec, io.out.map(_.req.ready)) && state === s_idle || reqInvalidAddr
   for (i <- 0 until io.out.length) {
     io.out(i).req.valid := outSelVec(i) && io.in.req.valid && state === s_idle
     io.out(i).req.bits := io.in.req.bits
@@ -68,7 +68,7 @@ class SimpleBusCrossbar1toN(addressSpace: List[(Long, Long)]) extends Module {
   for (i <- 0 until io.out.length) {
     io.out(i).resp.ready := outSelRespVec(i) && io.in.resp.ready && state === s_resp
   }
-  io.in.resp.valid := Mux1H(outSelRespVec, io.out.map(_.resp.valid)) || state === s_error
+  io.in.resp.valid := Mux1H(outSelRespVec, io.out.map(_.resp.valid)) && state === s_resp || state === s_error
   io.in.resp.bits := Mux1H(outSelRespVec, io.out.map(_.resp.bits))
   // io.in.resp.bits.exc.get := state === s_error
 
@@ -183,4 +183,4 @@ class SimpleBusAutoIDCrossbarNto1(n: Int, userBits: Int = 0) extends Module {
     }
   }
 
-}
\ No newline at end of file
+}