diff --git a/rocket/src/main/scala/btb.scala b/rocket/src/main/scala/btb.scala
index 7cf4094f..7cf24b5d 100644
--- a/rocket/src/main/scala/btb.scala
+++ b/rocket/src/main/scala/btb.scala
@@ -5,13 +5,13 @@ import Util._
 import Node._
 import uncore._
 
-case object BTBEntries extends Field[Int]
+case object NBTBEntries extends Field[Int]
 case object NRAS extends Field[Int] 
 
 abstract trait BTBParameters extends UsesParameters {
   val vaddrBits = params(VAddrBits)
   val matchBits = params(PgIdxBits)
-  val entries = params(BTBEntries)
+  val entries = params(NBTBEntries)
   val nRAS = params(NRAS)
   val nPages = ((1 max(log2Up(entries)))+1)/2*2 // control logic assumes 2 divides pages
   val opaqueBits = log2Up(entries)
diff --git a/rocket/src/main/scala/core.scala b/rocket/src/main/scala/core.scala
index 0b22b42a..a6dee39f 100644
--- a/rocket/src/main/scala/core.scala
+++ b/rocket/src/main/scala/core.scala
@@ -2,10 +2,34 @@ package rocket
 
 import Chisel._
 import Util._
-import uncore.HTIFIO
+import uncore._
 
-case object FPUParams extends Field[PF]
 case object BuildFPU extends Field[Option[() => FPU]]
+case object XprLen extends Field[Int]
+case object NMultXpr extends Field[Int]
+case object RetireWidth extends Field[Int]
+case object UseVM extends Field[Boolean]
+case object FastLoadWord extends Field[Boolean]
+case object FastLoadByte extends Field[Boolean]
+case object FastMulDiv extends Field[Boolean]
+case object CoreInstBits extends Field[Int]
+case object CoreDataBits extends Field[Int]
+case object CoreDCacheReqTagBits extends Field[Int]
+
+abstract trait CoreParameters extends UsesParameters {
+  val xprLen = params(XprLen)
+  val coreInstBits = params(CoreInstBits)
+  val coreInstBytes = coreInstBits/8
+  val coreDataBits = xprLen
+  val coreDataBytes = coreDataBits/8
+  val coreDCacheReqTagBits = params(CoreDCacheReqTagBits)
+  val coreMaxAddrBits = math.max(params(PPNBits),params(VPNBits)+1) + params(PgIdxBits)
+
+  if(params(FastLoadByte)) require(params(FastLoadWord))
+  require(params(RetireWidth) == 1) // for now...
+}
+abstract class CoreBundle extends Bundle with CoreParameters
+abstract class CoreModule extends Module with CoreParameters
 
 class RocketIO extends Bundle
 {
@@ -16,19 +40,20 @@ class RocketIO extends Bundle
   val rocc = new RoCCInterface().flip
 }
 
-class Core extends Module
+class Core extends Module with CoreParameters
 {
   val io = new RocketIO
    
   val ctrl = Module(new Control)
   val dpath = Module(new Datapath)
 
-  if (!params(BuildFPU).isEmpty) {
-    val p = Some(params.alter(params(FPUParams)))
-    val fpu = Module(params(BuildFPU).get())(p)
-    dpath.io.fpu <> fpu.io.dpath
-    ctrl.io.fpu <> fpu.io.ctrl
-  }
+  //If so specified, build an FPU module and wire it in
+  params(BuildFPU) 
+    .map { bf => Module(bf()) } 
+    .foreach { fpu => 
+      dpath.io.fpu <> fpu.io.dpath
+      ctrl.io.fpu <> fpu.io.ctrl
+    }
 
   ctrl.io.dpath <> dpath.io.ctrl
   dpath.io.host <> io.host
diff --git a/rocket/src/main/scala/dpath.scala b/rocket/src/main/scala/dpath.scala
index e932b1dd..84a0a400 100644
--- a/rocket/src/main/scala/dpath.scala
+++ b/rocket/src/main/scala/dpath.scala
@@ -171,7 +171,7 @@ class Datapath extends Module
   io.dmem.req.bits.addr := Cat(vaSign(ex_rs(0), alu.io.adder_out), alu.io.adder_out(params(VAddrBits)-1,0)).toUInt
   io.dmem.req.bits.tag := Cat(io.ctrl.ex_waddr, io.ctrl.ex_fp_val)
   require(io.dmem.req.bits.tag.getWidth >= 6)
-  require(params(DcacheReqTagBits) >= 6)
+  require(params(CoreDCacheReqTagBits) >= 6)
 
   // processor control regfile read
   val pcr = Module(new CSRFile)
diff --git a/rocket/src/main/scala/icache.scala b/rocket/src/main/scala/icache.scala
index aac6a21b..1f85a22b 100644
--- a/rocket/src/main/scala/icache.scala
+++ b/rocket/src/main/scala/icache.scala
@@ -4,29 +4,30 @@ import Chisel._
 import uncore._
 import Util._
 
-case object InstBytes extends Field[Int]
+case object NITLBEntries extends Field[Int]
+case object ECCCode extends Field[Option[Code]]
 
-abstract trait FrontendParameters extends CacheParameters {
-  val instBytes = params(InstBytes)
+abstract trait L1CacheParameters extends CacheParameters with CoreParameters {
   val co = params(TLCoherence)
-  val code = params(ECCCode)
-} 
+  val code = params(ECCCode).getOrElse(new IdentityCode)
+}
 
+abstract trait FrontendParameters extends L1CacheParameters
 abstract class FrontendBundle extends Bundle with FrontendParameters
 abstract class FrontendModule extends Module with FrontendParameters
 
-class FrontendReq extends FrontendBundle {
-  val pc = UInt(width = vaddrBits+1)
+class FrontendReq extends CoreBundle {
+  val pc = UInt(width = params(VAddrBits)+1)
 }
 
-class FrontendResp extends FrontendBundle {
-  val pc = UInt(width = vaddrBits+1)  // ID stage PC
-  val data = Bits(width = instBytes*8)
+class FrontendResp extends CoreBundle {
+  val pc = UInt(width = params(VAddrBits)+1)  // ID stage PC
+  val data = Bits(width = coreInstBits)
   val xcpt_ma = Bool()
   val xcpt_if = Bool()
 }
 
-class CPUFrontendIO extends FrontendBundle {
+class CPUFrontendIO extends CoreBundle {
   val req = Valid(new FrontendReq)
   val resp = Decoupled(new FrontendResp).flip
   val btb_resp = Valid(new BTBResp).flip
@@ -44,7 +45,7 @@ class Frontend extends FrontendModule
   
   val btb = Module(new BTB)
   val icache = Module(new ICache)
-  val tlb = Module(new TLB(params(NTLBEntries)))
+  val tlb = Module(new TLB(params(NITLBEntries)))
 
   val s1_pc_ = Reg(UInt())
   val s1_pc = s1_pc_ & SInt(-2) // discard LSB of PC (throughout the pipeline)
@@ -57,7 +58,7 @@ class Frontend extends FrontendModule
 
   val msb = vaddrBits-1
   val btbTarget = Cat(btb.io.resp.bits.target(msb), btb.io.resp.bits.target)
-  val pcp4_0 = s1_pc + UInt(instBytes)
+  val pcp4_0 = s1_pc + UInt(coreInstBytes)
   val pcp4 = Cat(s1_pc(msb) & pcp4_0(msb), pcp4_0(msb,0))
   val icmiss = s2_valid && !icache.io.resp.valid
   val predicted_npc = Mux(btb.io.resp.bits.taken, btbTarget, pcp4)
@@ -82,7 +83,7 @@ class Frontend extends FrontendModule
     s2_valid := Bool(false)
   }
 
-  btb.io.req := s1_pc & SInt(-instBytes)
+  btb.io.req := s1_pc & SInt(-coreInstBytes)
   btb.io.update := io.cpu.btb_update
   btb.io.invalidate := io.cpu.invalidate || io.cpu.ptw.invalidate
 
@@ -102,9 +103,9 @@ class Frontend extends FrontendModule
   icache.io.resp.ready := !stall && !s1_same_block
 
   io.cpu.resp.valid := s2_valid && (s2_xcpt_if || icache.io.resp.valid)
-  io.cpu.resp.bits.pc := s2_pc & SInt(-instBytes) // discard PC LSBs
-  io.cpu.resp.bits.data := icache.io.resp.bits.datablock >> (s2_pc(log2Up(rowBytes)-1,log2Up(instBytes)) << log2Up(instBytes*8))
-  io.cpu.resp.bits.xcpt_ma := s2_pc(log2Up(instBytes)-1,0) != UInt(0)
+  io.cpu.resp.bits.pc := s2_pc & SInt(-coreInstBytes) // discard PC LSBs
+  io.cpu.resp.bits.data := icache.io.resp.bits.datablock >> (s2_pc(log2Up(rowBytes)-1,log2Up(coreInstBytes)) << log2Up(coreInstBits))
+  io.cpu.resp.bits.xcpt_ma := s2_pc(log2Up(coreInstBytes)-1,0) != UInt(0)
   io.cpu.resp.bits.xcpt_if := s2_xcpt_if
 
   io.cpu.btb_resp.valid := s2_btb_resp_valid
@@ -118,7 +119,7 @@ class ICacheReq extends FrontendBundle {
 }
 
 class ICacheResp extends FrontendBundle {
-  val data = Bits(width = instBytes*8)
+  val data = Bits(width = coreInstBits)
   val datablock = Bits(width = rowBits)
 }
 
@@ -131,7 +132,7 @@ class ICache extends FrontendModule
     val mem = new UncachedTileLinkIO
   }
   require(isPow2(nSets) && isPow2(nWays))
-  require(isPow2(instBytes))
+  require(isPow2(coreInstBytes))
   require(pgIdxBits >= untagBits)
 
   val s_ready :: s_request :: s_refill_wait :: s_refill :: Nil = Enum(UInt(), 4)
@@ -249,7 +250,7 @@ class ICache extends FrontendModule
     // if s1_tag_match is critical, replace with partial tag check
     when (s1_valid && rdy && !stall && (Bool(isDM) || s1_tag_match(i))) { s2_dout(i) := data_array(s1_raddr) }
   }
-  val s2_dout_word = s2_dout.map(x => (x >> (s2_offset(log2Up(rowBytes)-1,log2Up(instBytes)) << log2Up(instBytes*8)))(instBytes*8-1,0))
+  val s2_dout_word = s2_dout.map(x => (x >> (s2_offset(log2Up(rowBytes)-1,log2Up(coreInstBytes)) << log2Up(coreInstBits)))(coreInstBits-1,0))
   io.resp.bits.data := Mux1H(s2_tag_hit, s2_dout_word)
   io.resp.bits.datablock := Mux1H(s2_tag_hit, s2_dout)
 
diff --git a/rocket/src/main/scala/multiplier.scala b/rocket/src/main/scala/multiplier.scala
index 02cf199c..6a595c4b 100644
--- a/rocket/src/main/scala/multiplier.scala
+++ b/rocket/src/main/scala/multiplier.scala
@@ -9,12 +9,12 @@ class MultiplierReq extends Bundle {
   val dw = Bits(width = SZ_DW)
   val in1 = Bits(width = params(XprLen))
   val in2 = Bits(width = params(XprLen))
-  val tag = UInt(width = params(NXprBits))
+  val tag = UInt(width = log2Up(params(NMultXpr)))
 }
 
 class MultiplierResp extends Bundle {
   val data = Bits(width = params(XprLen))
-  val tag = UInt(width = params(NXprBits))
+  val tag = UInt(width = log2Up(params(NMultXpr)))
 }
 
 class MultiplierIO extends Bundle {
diff --git a/rocket/src/main/scala/nbdcache.scala b/rocket/src/main/scala/nbdcache.scala
index b1a44d0c..cdf360c4 100644
--- a/rocket/src/main/scala/nbdcache.scala
+++ b/rocket/src/main/scala/nbdcache.scala
@@ -7,25 +7,14 @@ import Util._
 case object StoreDataQueueDepth extends Field[Int]
 case object ReplayQueueDepth extends Field[Int]
 case object NMSHRs extends Field[Int]
-case object CoreReqTagBits extends Field[Int]
-case object CoreDataBits extends Field[Int]
 case object LRSCCycles extends Field[Int]
-//TODO PARAMS Also used by icache: is this ok?:
-case object NTLBEntries extends Field[Int]
-case object ECCCode extends Field[Code]
+case object NDTLBEntries extends Field[Int]
 
-abstract trait L1HellaCacheParameters extends CacheParameters {
+abstract trait L1HellaCacheParameters extends L1CacheParameters {
   val indexmsb = untagBits-1
   val indexlsb = blockOffBits
   val offsetmsb = indexlsb-1
   val offsetlsb = wordOffBits
-
-  val co = params(TLCoherence)
-  val code = params(ECCCode)
-  val coreReqTagBits = params(CoreReqTagBits)
-  val coreDataBits = params(CoreDataBits)
-  val maxAddrBits = math.max(params(PPNBits),params(VPNBits)+1) + params(PgIdxBits)
-  val coreDataBytes = coreDataBits/8
   val doNarrowRead = coreDataBits * nWays % rowBits == 0
   val encDataBits = code.width(coreDataBits)
   val encRowBits = encDataBits*rowWords
@@ -66,26 +55,26 @@ class LoadGen(typ: Bits, addr: Bits, dat: Bits, zero: Bool)
   val byte = Cat(Mux(zero || t.byte, Fill(56, sign && byteShift(7)), half(63,8)), byteShift)
 }
 
-class HellaCacheReq extends L1HellaCacheBundle {
+class HellaCacheReq extends CoreBundle {
   val kill = Bool()
   val typ  = Bits(width = MT_SZ)
   val phys = Bool()
-  val addr = UInt(width = maxAddrBits)
+  val addr = UInt(width = coreMaxAddrBits)
   val data = Bits(width = coreDataBits)
-  val tag  = Bits(width = coreReqTagBits)
+  val tag  = Bits(width = coreDCacheReqTagBits)
   val cmd  = Bits(width = M_SZ)
 }
 
-class HellaCacheResp extends L1HellaCacheBundle {
+class HellaCacheResp extends CoreBundle {
   val nack = Bool() // comes 2 cycles after req.fire
   val replay = Bool()
   val typ = Bits(width = 3)
   val has_data = Bool()
   val data = Bits(width = coreDataBits)
   val data_subword = Bits(width = coreDataBits)
-  val tag = Bits(width = coreReqTagBits)
+  val tag = Bits(width = coreDCacheReqTagBits)
   val cmd  = Bits(width = 4)
-  val addr = UInt(width = maxAddrBits)
+  val addr = UInt(width = coreMaxAddrBits)
   val store_data = Bits(width = coreDataBits)
 }
 
@@ -100,22 +89,22 @@ class HellaCacheExceptions extends Bundle {
 }
 
 // interface between D$ and processor/DTLB
-class HellaCacheIO extends L1HellaCacheBundle {
+class HellaCacheIO extends CoreBundle {
   val req = Decoupled(new HellaCacheReq)
   val resp = Valid(new HellaCacheResp).flip
-  val replay_next = Valid(Bits(width = coreReqTagBits)).flip
+  val replay_next = Valid(Bits(width = coreDCacheReqTagBits)).flip
   val xcpt = (new HellaCacheExceptions).asInput
   val ptw = new TLBPTWIO().flip
   val ordered = Bool(INPUT)
 }
 
-class MSHRReq extends HellaCacheReq {
+class MSHRReq extends HellaCacheReq with L1HellaCacheParameters {
   val tag_match = Bool()
   val old_meta = new L1Metadata
   val way_en = Bits(width = nWays)
 }
 
-class Replay extends HellaCacheReq {
+class Replay extends HellaCacheReq with L1HellaCacheParameters {
   val sdq_id = UInt(width = log2Up(params(StoreDataQueueDepth)))
 }
 
@@ -704,7 +693,7 @@ class HellaCache extends L1HellaCacheModule {
   val s1_sc = s1_req.cmd === M_XSC
   val s1_readwrite = s1_read || s1_write || isPrefetch(s1_req.cmd)
 
-  val dtlb = Module(new TLB(params(NTLBEntries)))
+  val dtlb = Module(new TLB(params(NDTLBEntries)))
   dtlb.io.ptw <> io.cpu.ptw
   dtlb.io.req.valid := s1_valid_masked && s1_readwrite && !s1_req.phys
   dtlb.io.req.bits.passthrough := s1_req.phys
diff --git a/rocket/src/main/scala/tile.scala b/rocket/src/main/scala/tile.scala
index d0f49fbe..0b54af00 100644
--- a/rocket/src/main/scala/tile.scala
+++ b/rocket/src/main/scala/tile.scala
@@ -4,44 +4,24 @@ import Chisel._
 import uncore._
 import Util._
 
+case object WhichL1Cache extends Field[String]
 case object NDCachePorts extends Field[Int]
 case object NTilePorts extends Field[Int]
+case object NPTWPorts extends Field[Int]
 case object BuildRoCC extends Field[Option[() => RoCC]]
-case object RetireWidth extends Field[Int]
-case object UseVM extends Field[Boolean]
-case object FastLoadWord extends Field[Boolean]
-case object FastLoadByte extends Field[Boolean]
-case object FastMulDiv extends Field[Boolean]
-case object DcacheReqTagBits extends Field[Int]
-case object XprLen extends Field[Int]
-case object NXpr extends Field[Int]
-case object NXprBits extends Field[Int]
-case object RocketDCacheParams extends Field[PF]
-case object RocketFrontendParams extends Field[PF]
 
 class Tile(resetSignal: Bool = null) extends Module(_reset = resetSignal) {
-
-  if(params(FastLoadByte)) require(params(FastLoadWord))
-  require(params(RetireWidth) == 1) // for now...
-
   val io = new Bundle {
     val tilelink = new TileLinkIO
     val host = new HTIFIO
   }
-  // Mimic client id extension done by UncachedTileLinkIOArbiter for Acquires from either client)
 
-  val optionalRoCC = params(BuildRoCC)
+  val icache = Module(new Frontend, { case CacheName => "L1I" })
+  val dcache = Module(new HellaCache, { case CacheName => "L1D" })
+  val ptw = Module(new PTW(params(NPTWPorts)))
+  val core = Module(new Core)
 
-  val p = params.alter(params(RocketFrontendParams)) // Used in icache, Core
-  val icache = Module(new Frontend)(p) //TODO PARAMS: best way to alter both?
-  val p2 = params.alter(params(RocketDCacheParams)) // Used in dcache, PTW, RoCCm Core
-  val dcache = Module(new HellaCache)(p2)
-  val ptw = Module(new PTW(if(optionalRoCC.isEmpty) 2 else 5))(p2)
-    // 2 ports, 1 from I$, 1 from D$, maybe 3 from RoCC
-  val p3 = params.alter(params(RocketFrontendParams)).alter(params(RocketDCacheParams))
-  val core = Module(new Core)(p3)
-
-  val dcArb = Module(new HellaCacheArbiter(params(NDCachePorts)))(p2)
+  val dcArb = Module(new HellaCacheArbiter(params(NDCachePorts)))
   dcArb.io.requestor(0) <> ptw.io.mem
   dcArb.io.requestor(1) <> core.io.dmem
   dcArb.io.mem <> dcache.io.cpu
@@ -58,17 +38,19 @@ class Tile(resetSignal: Bool = null) extends Module(_reset = resetSignal) {
   memArb.io.in(dcPortId) <> dcache.io.mem
   memArb.io.in(1) <> icache.io.mem
 
-  if(!optionalRoCC.isEmpty) {
-    val rocc = Module(optionalRoCC.get())
-    val dcIF = Module(new SimpleHellaCacheIF)
-    dcIF.io.requestor <> rocc.io.mem
-    core.io.rocc <> rocc.io
-    dcArb.io.requestor(2) <> dcIF.io.cache
-    memArb.io.in(2) <> rocc.io.imem
-    ptw.io.requestor(2) <> rocc.io.iptw
-    ptw.io.requestor(3) <> rocc.io.dptw
-    ptw.io.requestor(4) <> rocc.io.pptw
-  }
+  //If so specified, build an RoCC module and wire it in
+  params(BuildRoCC)
+    .map { br => Module(br()) }
+    .foreach { rocc =>
+      val dcIF = Module(new SimpleHellaCacheIF)
+      dcIF.io.requestor <> rocc.io.mem
+      core.io.rocc <> rocc.io
+      dcArb.io.requestor(2) <> dcIF.io.cache
+      memArb.io.in(2) <> rocc.io.imem
+      ptw.io.requestor(2) <> rocc.io.iptw
+      ptw.io.requestor(3) <> rocc.io.dptw
+      ptw.io.requestor(4) <> rocc.io.pptw
+    }
  
   io.tilelink.acquire <> memArb.io.out.acquire
   io.tilelink.grant <> memArb.io.out.grant