From 891e459625f00485830303148ab83227ed6afdb0 Mon Sep 17 00:00:00 2001
From: Stephen Twigg <sdtwigg@eecs.berkeley.edu>
Date: Wed, 25 Sep 2013 01:16:32 -0700
Subject: [PATCH] Export stats pcr register (#28 currently) to the top-level

---
 rocket/src/main/scala/dpath_util.scala | 4 ++--
 rocket/src/main/scala/htif.scala       | 7 +++++++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/rocket/src/main/scala/dpath_util.scala b/rocket/src/main/scala/dpath_util.scala
index 7528cead..a5dffc45 100644
--- a/rocket/src/main/scala/dpath_util.scala
+++ b/rocket/src/main/scala/dpath_util.scala
@@ -133,7 +133,6 @@ class PCR(implicit conf: RocketConfiguration) extends Module
     val irq_timer = Bool(OUTPUT)
     val irq_ipi = Bool(OUTPUT)
     val replay = Bool(OUTPUT)
-    val stats = Bool(OUTPUT)
   }
   import PCR._
  
@@ -171,6 +170,8 @@ class PCR(implicit conf: RocketConfiguration) extends Module
     host_pcr_bits.data := io.rw.rdata
   }
   when (io.host.pcr_rep.fire()) { host_pcr_rep_valid := false }
+  
+  io.host.debug_stats_pcr := reg_stats // direct export up the hierarchy
 
   val addr = Mux(io.rw.cmd != PCR.N, io.rw.addr, host_pcr_bits.addr)
   val wen = io.rw.cmd === PCR.T || io.rw.cmd === PCR.S || io.rw.cmd === PCR.C ||
@@ -183,7 +184,6 @@ class PCR(implicit conf: RocketConfiguration) extends Module
   io.fatc := wen && addr === FATC
   io.evec := Mux(io.exception, reg_evec.toSInt, reg_epc).toUInt
   io.ptbr := reg_ptbr
-  io.stats := reg_stats
 
   when (io.badvaddr_wen) {
     val wdata = io.rw.wdata
diff --git a/rocket/src/main/scala/htif.scala b/rocket/src/main/scala/htif.scala
index 05a9bef6..a0085ac3 100644
--- a/rocket/src/main/scala/htif.scala
+++ b/rocket/src/main/scala/htif.scala
@@ -11,6 +11,7 @@ class HostIO(val w: Int) extends Bundle
   val clk_edge = Bool(OUTPUT)
   val in = Decoupled(Bits(width = w)).flip
   val out = Decoupled(Bits(width = w))
+  val debug_stats_pcr = Bool(OUTPUT)
 }
 
 class PCRReq extends Bundle
@@ -28,6 +29,9 @@ class HTIFIO(ntiles: Int) extends Bundle
   val pcr_rep = Decoupled(Bits(width = 64))
   val ipi_req = Decoupled(Bits(width = log2Up(ntiles)))
   val ipi_rep = Decoupled(Bool()).flip
+  val debug_stats_pcr = Bool(OUTPUT)
+    // wired directly to stats register
+    // expected to be used to quickly indicate to testbench to do logging b/c in 'interesting' work
 }
 
 class SCRIO(n: Int) extends Bundle
@@ -49,6 +53,9 @@ class RocketHTIF(w: Int, nSCR: Int)(implicit conf: TileLinkConfiguration) extend
     val scr = new SCRIO(nSCR)
   }
 
+  io.host.debug_stats_pcr := io.cpu.map(_.debug_stats_pcr).reduce(_||_)
+    // system is 'interesting' if any tile is 'interesting'
+
   val short_request_bits = 64
   val long_request_bits = 576
   require(short_request_bits % w == 0)