Merge pull request #197 from ucb-bar/lowercaseChisel

Rename package Chisel to chisel, add Chisel package for compatibility

63 files changed, 419 insertions, 127 deletions

diff --git a/src/main/scala/Chisel/package.scala b/src/main/scala/Chisel/package.scala
deleted file mode 100644
index f05e8b5d..00000000
--- a/src/main/scala/Chisel/package.scala
+++ /dev/null
@@ -1,31 +0,0 @@
-package object Chisel {
-  import scala.language.experimental.macros
-  
-  import internal.firrtl.Width
-  import internal.sourceinfo.{SourceInfo, SourceInfoTransform}
-  
-  implicit class fromBigIntToLiteral(val x: BigInt) extends AnyVal {
-    def U: UInt = UInt(x, Width())
-    def S: SInt = SInt(x, Width())
-  }
-  implicit class fromIntToLiteral(val x: Int) extends AnyVal {
-    def U: UInt = UInt(BigInt(x), Width())
-    def S: SInt = SInt(BigInt(x), Width())
-  }
-  implicit class fromStringToLiteral(val x: String) extends AnyVal {
-    def U: UInt = UInt(x)
-  }
-  implicit class fromBooleanToLiteral(val x: Boolean) extends AnyVal {
-    def B: Bool = Bool(x)
-  }
-  
-  implicit class fromUIntToBitPatComparable(val x: UInt) extends AnyVal {
-    final def === (that: BitPat): Bool = macro SourceInfoTransform.thatArg
-    final def != (that: BitPat): Bool = macro SourceInfoTransform.thatArg
-    final def =/= (that: BitPat): Bool = macro SourceInfoTransform.thatArg
-  
-    def do_=== (that: BitPat)(implicit sourceInfo: SourceInfo): Bool = that === x
-    def do_!= (that: BitPat)(implicit sourceInfo: SourceInfo): Bool = that != x
-    def do_=/= (that: BitPat)(implicit sourceInfo: SourceInfo): Bool = that =/= x
-  }
-}
diff --git a/src/main/scala/Chisel/Driver.scala b/src/main/scala/chisel/Driver.scala
index 02204684..ba2b1389 100644
--- a/src/main/scala/Chisel/Driver.scala
+++ b/src/main/scala/chisel/Driver.scala
@@ -1,6 +1,6 @@
 // See LICENSE for license details.
 
-package Chisel
+package chisel
 
 import scala.sys.process._
 import java.io._
diff --git a/src/main/scala/chisel/compatibility.scala b/src/main/scala/chisel/compatibility.scala
new file mode 100644
index 00000000..56088562
--- /dev/null
+++ b/src/main/scala/chisel/compatibility.scala
@@ -0,0 +1,150 @@
+// See LICENSE for license details.
+
+// Allows legacy users to continue using Chisel (capital C) package name while
+// moving to the more standard package naming convention chisel (lowercase c).
+
+package object Chisel {
+  type Direction = chisel.core.Direction
+  val INPUT = chisel.core.INPUT
+  val OUTPUT = chisel.core.OUTPUT
+  val NO_DIR = chisel.core.NO_DIR
+
+  type Flipped = chisel.core.Flipped
+  type Data = chisel.core.Data
+  val Wire = chisel.core.Wire
+  val Clock = chisel.core.Clock
+  type Clock = chisel.core.Clock
+
+  type Aggregate = chisel.core.Aggregate
+  val Vec = chisel.core.Vec
+  type Vec[T <: Data] = chisel.core.Vec[T]
+  type VecLike[T <: Data] = chisel.core.VecLike[T]
+  type Bundle = chisel.core.Bundle
+
+  val assert = chisel.core.assert
+
+  type Element = chisel.core.Element
+  type Bits = chisel.core.Bits
+  val Bits = chisel.core.Bits
+  type Num[T <: Data] = chisel.core.Num[T]
+  type UInt = chisel.core.UInt
+  val UInt = chisel.core.UInt
+  type SInt = chisel.core.SInt
+  val SInt = chisel.core.SInt
+  type Bool = chisel.core.Bool
+  val Bool = chisel.core.Bool
+  val Mux = chisel.core.Mux
+
+  type BlackBox = chisel.core.BlackBox
+
+  val Mem = chisel.core.Mem
+  type MemBase[T <: Data] = chisel.core.MemBase[T]
+  type Mem[T <: Data] = chisel.core.Mem[T]
+  val SeqMem = chisel.core.SeqMem
+  type SeqMem[T <: Data] = chisel.core.SeqMem[T]
+
+  val Module = chisel.core.Module
+  type Module = chisel.core.Module
+
+  val printf = chisel.core.printf
+
+  val Reg = chisel.core.Reg
+
+  val when = chisel.core.when
+  type WhenContext = chisel.core.WhenContext
+
+
+  type BackendCompilationUtilities = chisel.BackendCompilationUtilities
+  val Driver = chisel.Driver
+  type FileSystemUtilities = chisel.compatibility.FileSystemUtilities
+  val ImplicitConversions = chisel.util.ImplicitConversions
+  val chiselMain = chisel.compatibility.chiselMain
+  val throwException = chisel.compatibility.throwException
+  val debug = chisel.compatibility.debug
+
+  object testers {
+    type BasicTester = chisel.testers.BasicTester
+    val TesterDriver = chisel.testers.TesterDriver
+  }
+
+
+  val log2Up = chisel.util.log2Up
+  val log2Ceil = chisel.util.log2Ceil
+  val log2Down = chisel.util.log2Down
+  val log2Floor = chisel.util.log2Floor
+  val isPow2 = chisel.util.isPow2
+
+  val BitPat = chisel.util.BitPat
+  type BitPat = chisel.util.BitPat
+
+  type ArbiterIO[T <: Data] = chisel.util.ArbiterIO[T]
+  type LockingArbiterLike[T <: Data] = chisel.util.LockingArbiterLike[T]
+  type LockingRRArbiter[T <: Data] = chisel.util.LockingRRArbiter[T]
+  type LockingArbiter[T <: Data] = chisel.util.LockingArbiter[T]
+  type RRArbiter[T <: Data] = chisel.util.RRArbiter[T]
+  type Arbiter[T <: Data] = chisel.util.Arbiter[T]
+
+  val FillInterleaved = chisel.util.FillInterleaved
+  val PopCount = chisel.util.PopCount
+  val Fill = chisel.util.Fill
+  val Reverse = chisel.util.Reverse
+
+  val Cat = chisel.util.Cat
+
+  val Log2 = chisel.util.Log2
+
+  val unless = chisel.util.unless
+  type SwitchContext[T <: Bits] = chisel.util.SwitchContext[T]
+  val is = chisel.util.is
+  val switch = chisel.util.switch
+
+  type Counter = chisel.util.Counter
+  val Counter = chisel.util.Counter
+
+  type DecoupledIO[+T <: Data] = chisel.util.DecoupledIO[T]
+  val Decoupled = chisel.util.Decoupled
+  type EnqIO[T <: Data] = chisel.util.EnqIO[T]
+  type DeqIO[T <: Data] = chisel.util.DeqIO[T]
+  type DecoupledIOC[+T <: Data] = chisel.util.DecoupledIOC[T]
+  type QueueIO[T <: Data] = chisel.util.QueueIO[T]
+  type Queue[T <: Data] = chisel.util.Queue[T]
+  val Queue = chisel.util.Queue
+
+  val Enum = chisel.util.Enum
+
+  val LFSR16 = chisel.util.LFSR16
+
+  val ListLookup = chisel.util.ListLookup
+  val Lookup = chisel.util.Lookup
+
+  val Mux1H = chisel.util.Mux1H
+  val PriorityMux = chisel.util.PriorityMux
+  val MuxLookup = chisel.util.MuxLookup
+  val MuxCase = chisel.util.MuxCase
+
+  val OHToUInt = chisel.util.OHToUInt
+  val PriorityEncoder = chisel.util.PriorityEncoder
+  val UIntToOH = chisel.util.UIntToOH
+  val PriorityEncoderOH = chisel.util.PriorityEncoderOH
+
+  val RegNext = chisel.util.RegNext
+  val RegInit = chisel.util.RegInit
+  val RegEnable = chisel.util.RegEnable
+  val ShiftRegister = chisel.util.ShiftRegister
+
+  type ValidIO[+T <: Data] = chisel.util.ValidIO[T]
+  val Valid = chisel.util.Valid
+  val Pipe = chisel.util.Pipe
+  type Pipe[T <: Data] = chisel.util.Pipe[T]
+
+
+  import chisel.internal.firrtl.Width
+  implicit def fromBigIntToLiteral(x: BigInt): chisel.fromBigIntToLiteral =
+    new chisel.fromBigIntToLiteral(x)
+  implicit def fromIntToLiteral(x: Int): chisel.fromIntToLiteral=
+    new chisel.fromIntToLiteral(x)
+  implicit def fromStringToLiteral(x: String): chisel.fromStringToLiteral=
+    new chisel.fromStringToLiteral(x)
+  implicit def fromBooleanToLiteral(x: Boolean): chisel.fromBooleanToLiteral=
+    new chisel.fromBooleanToLiteral(x)
+}
diff --git a/src/main/scala/Chisel/FileSystemUtilities.scala b/src/main/scala/chisel/compatibility/FileSystemUtilities.scala
index 575ae138..d12e627d 100644
--- a/src/main/scala/Chisel/FileSystemUtilities.scala
+++ b/src/main/scala/chisel/compatibility/FileSystemUtilities.scala
@@ -1,6 +1,8 @@
 // See LICENSE for license details.
 
-package Chisel
+package chisel.compatibility
+
+import chisel._
 
 @deprecated("FileSystemUtilities doesn't exist in chisel3", "3.0.0")
 trait FileSystemUtilities {
diff --git a/src/main/scala/Chisel/Main.scala b/src/main/scala/chisel/compatibility/Main.scala
index a72debc3..9072bfcf 100644
--- a/src/main/scala/Chisel/Main.scala
+++ b/src/main/scala/chisel/compatibility/Main.scala
@@ -1,9 +1,11 @@
 // See LICENSE for license details.
 
-package Chisel
+package chisel.compatibility
 
 import java.io.File
 
+import chisel._
+
 @deprecated("chiselMain doesn't exist in Chisel3", "3.0") object chiselMain {
   def apply[T <: Module](args: Array[String], gen: () => T): Unit =
     Predef.assert(false, "No more chiselMain in Chisel3")
diff --git a/src/main/scala/chisel/compatibility/debug.scala b/src/main/scala/chisel/compatibility/debug.scala
new file mode 100644
index 00000000..8850c76b
--- /dev/null
+++ b/src/main/scala/chisel/compatibility/debug.scala
@@ -0,0 +1,8 @@
+package chisel.compatibility
+
+import chisel.core._
+
+@deprecated("debug doesn't do anything in Chisel3 as no pruning happens in the frontend", "chisel3")
+object debug {  // scalastyle:ignore object.name
+  def apply (arg: Data): Data = arg
+}
diff --git a/src/main/scala/Chisel/throwException.scala b/src/main/scala/chisel/compatibility/throwException.scala
index 702884aa..3b9fd06e 100644
--- a/src/main/scala/Chisel/throwException.scala
+++ b/src/main/scala/chisel/compatibility/throwException.scala
@@ -1,6 +1,8 @@
 // See LICENSE for license details.
 
-package Chisel
+package chisel.compatibility
+
+import chisel._
 
 @deprecated("throwException doesn't exist in Chisel3", "3.0.0")
 @throws(classOf[Exception])
diff --git a/src/main/scala/Chisel/internal/firrtl/Emitter.scala b/src/main/scala/chisel/internal/firrtl/Emitter.scala
index 7ca3268a..e48eb226 100644
--- a/src/main/scala/Chisel/internal/firrtl/Emitter.scala
+++ b/src/main/scala/chisel/internal/firrtl/Emitter.scala
@@ -1,10 +1,10 @@
 // See LICENSE for license details.
 
-package Chisel.internal.firrtl
-import Chisel._
-import Chisel.internal.sourceinfo.{NoSourceInfo, SourceLine}
+package chisel.internal.firrtl
+import chisel._
+import chisel.internal.sourceinfo.{NoSourceInfo, SourceLine}
 
-private[Chisel] object Emitter {
+private[chisel] object Emitter {
   def emit(circuit: Circuit): String = new Emitter(circuit).toString
 }
 
diff --git a/src/main/scala/chisel/package.scala b/src/main/scala/chisel/package.scala
new file mode 100644
index 00000000..f7ed6b13
--- /dev/null
+++ b/src/main/scala/chisel/package.scala
@@ -0,0 +1,82 @@
+package object chisel {
+  import scala.language.experimental.macros
+
+  import internal.firrtl.Width
+  import internal.sourceinfo.{SourceInfo, SourceInfoTransform}
+  import util.BitPat
+
+
+  type Direction = chisel.core.Direction
+  val INPUT = chisel.core.INPUT
+  val OUTPUT = chisel.core.OUTPUT
+  val NO_DIR = chisel.core.NO_DIR
+  type Flipped = chisel.core.Flipped
+  type Data = chisel.core.Data
+  val Wire = chisel.core.Wire
+  val Clock = chisel.core.Clock
+  type Clock = chisel.core.Clock
+
+  type Aggregate = chisel.core.Aggregate
+  val Vec = chisel.core.Vec
+  type Vec[T <: Data] = chisel.core.Vec[T]
+  type VecLike[T <: Data] = chisel.core.VecLike[T]
+  type Bundle = chisel.core.Bundle
+
+  val assert = chisel.core.assert
+
+  type Element = chisel.core.Element
+  type Bits = chisel.core.Bits
+  val Bits = chisel.core.Bits
+  type Num[T <: Data] = chisel.core.Num[T]
+  type UInt = chisel.core.UInt
+  val UInt = chisel.core.UInt
+  type SInt = chisel.core.SInt
+  val SInt = chisel.core.SInt
+  type Bool = chisel.core.Bool
+  val Bool = chisel.core.Bool
+  val Mux = chisel.core.Mux
+
+  type BlackBox = chisel.core.BlackBox
+
+  val Mem = chisel.core.Mem
+  type MemBase[T <: Data] = chisel.core.MemBase[T]
+  type Mem[T <: Data] = chisel.core.Mem[T]
+  val SeqMem = chisel.core.SeqMem
+  type SeqMem[T <: Data] = chisel.core.SeqMem[T]
+
+  val Module = chisel.core.Module
+  type Module = chisel.core.Module
+
+  val printf = chisel.core.printf
+
+  val Reg = chisel.core.Reg
+
+  val when = chisel.core.when
+  type WhenContext = chisel.core.WhenContext
+
+
+  implicit class fromBigIntToLiteral(val x: BigInt) extends AnyVal {
+    def U: UInt = UInt(x, Width())
+    def S: SInt = SInt(x, Width())
+  }
+  implicit class fromIntToLiteral(val x: Int) extends AnyVal {
+    def U: UInt = UInt(BigInt(x), Width())
+    def S: SInt = SInt(BigInt(x), Width())
+  }
+  implicit class fromStringToLiteral(val x: String) extends AnyVal {
+    def U: UInt = UInt(x)
+  }
+  implicit class fromBooleanToLiteral(val x: Boolean) extends AnyVal {
+    def B: Bool = Bool(x)
+  }
+
+  implicit class fromUIntToBitPatComparable(val x: UInt) extends AnyVal {
+    final def === (that: BitPat): Bool = macro SourceInfoTransform.thatArg
+    final def != (that: BitPat): Bool = macro SourceInfoTransform.thatArg
+    final def =/= (that: BitPat): Bool = macro SourceInfoTransform.thatArg
+
+    def do_=== (that: BitPat)(implicit sourceInfo: SourceInfo): Bool = that === x
+    def do_!= (that: BitPat)(implicit sourceInfo: SourceInfo): Bool = that != x
+    def do_=/= (that: BitPat)(implicit sourceInfo: SourceInfo): Bool = that =/= x
+  }
+}
diff --git a/src/main/scala/Chisel/testers/BasicTester.scala b/src/main/scala/chisel/testers/BasicTester.scala
index b8c1494a..36ff7c52 100644
--- a/src/main/scala/Chisel/testers/BasicTester.scala
+++ b/src/main/scala/chisel/testers/BasicTester.scala
@@ -1,7 +1,7 @@
 // See LICENSE for license details.
 
-package Chisel.testers
-import Chisel._
+package chisel.testers
+import chisel._
 
 import scala.language.experimental.macros
 
diff --git a/src/main/scala/Chisel/testers/TesterDriver.scala b/src/main/scala/chisel/testers/TesterDriver.scala
index a56bb8b7..5c0275e0 100644
--- a/src/main/scala/Chisel/testers/TesterDriver.scala
+++ b/src/main/scala/chisel/testers/TesterDriver.scala
@@ -1,7 +1,8 @@
 // See LICENSE for license details.
 
-package Chisel.testers
-import Chisel._
+package chisel.testers
+
+import chisel._
 import scala.io.Source
 import scala.sys.process._
 import java.io._
diff --git a/src/main/scala/Chisel/util/Arbiter.scala b/src/main/scala/chisel/util/Arbiter.scala
index 16ae9be5..3723f2a9 100644
--- a/src/main/scala/Chisel/util/Arbiter.scala
+++ b/src/main/scala/chisel/util/Arbiter.scala
@@ -3,7 +3,9 @@
 /** Arbiters in all shapes and sizes.
   */
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 /** An I/O bundle for the Arbiter */
 class ArbiterIO[T <: Data](gen: T, n: Int) extends Bundle {
diff --git a/src/main/scala/Chisel/BitPat.scala b/src/main/scala/chisel/util/BitPat.scala
index 96206f63..13bbe1b0 100644
--- a/src/main/scala/Chisel/BitPat.scala
+++ b/src/main/scala/chisel/util/BitPat.scala
@@ -1,10 +1,11 @@
 // See LICENSE for license details.
 
-package Chisel
+package chisel.util
 
 import scala.language.experimental.macros
 
-import Chisel.internal.sourceinfo.{SourceInfo, SourceInfoTransform}
+import chisel._
+import chisel.internal.sourceinfo.{SourceInfo, SourceInfoTransform}
 
 object BitPat {
   /** Parses a bit pattern string into (bits, mask, width).
diff --git a/src/main/scala/Chisel/util/Bitwise.scala b/src/main/scala/chisel/util/Bitwise.scala
index 239a295e..d7d62ea3 100644
--- a/src/main/scala/Chisel/util/Bitwise.scala
+++ b/src/main/scala/chisel/util/Bitwise.scala
@@ -3,7 +3,10 @@
 /** Miscellaneous circuit generators operating on bits.
   */
 
-package Chisel
+package chisel.util
+
+import chisel._
+import chisel.core.SeqUtils
 
 object FillInterleaved
 {
diff --git a/src/main/scala/Chisel/util/Cat.scala b/src/main/scala/chisel/util/Cat.scala
index dd706e62..b47da706 100644
--- a/src/main/scala/Chisel/util/Cat.scala
+++ b/src/main/scala/chisel/util/Cat.scala
@@ -1,6 +1,9 @@
 // See LICENSE for license details.
 
-package Chisel
+package chisel.util
+
+import chisel._
+import chisel.core.SeqUtils
 
 object Cat {
   /** Combine data elements together
diff --git a/src/main/scala/Chisel/util/CircuitMath.scala b/src/main/scala/chisel/util/CircuitMath.scala
index 06cab903..c3b94fdb 100644
--- a/src/main/scala/Chisel/util/CircuitMath.scala
+++ b/src/main/scala/chisel/util/CircuitMath.scala
@@ -3,7 +3,9 @@
 /** Circuit-land math operations.
   */
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 /** Compute Log2 with truncation of a UInt in hardware using a Mux Tree
   * An alternative interpretation is it computes the minimum number of bits needed to represent x
diff --git a/src/main/scala/Chisel/util/Conditional.scala b/src/main/scala/chisel/util/Conditional.scala
index 9cab25ef..01c12799 100644
--- a/src/main/scala/Chisel/util/Conditional.scala
+++ b/src/main/scala/chisel/util/Conditional.scala
@@ -3,13 +3,15 @@
 /** Conditional blocks.
   */
 
-package Chisel
+package chisel.util
 
 import scala.language.reflectiveCalls
 import scala.language.experimental.macros
 import scala.reflect.runtime.universe._
 import scala.reflect.macros.blackbox._
 
+import chisel._
+
 /** This is identical to [[Chisel.when when]] with the condition inverted */
 object unless {  // scalastyle:ignore object.name
   def apply(c: Bool)(block: => Unit) {
@@ -59,7 +61,9 @@ object switch {  // scalastyle:ignore object.name
   def impl(c: Context)(cond: c.Tree)(x: c.Tree): c.Tree = { import c.universe._
     val sc = c.universe.internal.reificationSupport.freshTermName("sc")
     def extractIsStatement(tree: Tree): List[c.universe.Tree] = tree match {
-      case q"Chisel.is.apply( ..$params )( ..$body )" => List(q"$sc.is( ..$params )( ..$body )")
+      // TODO: remove when Chisel compatibility package is removed
+      case q"Chisel.`package`.is.apply( ..$params )( ..$body )" => List(q"$sc.is( ..$params )( ..$body )")
+      case q"chisel.util.is.apply( ..$params )( ..$body )" => List(q"$sc.is( ..$params )( ..$body )")
       case b => throw new Exception(s"Cannot include blocks that do not begin with is() in switch.")
     }
     val q"..$body" = x
diff --git a/src/main/scala/Chisel/util/Counter.scala b/src/main/scala/chisel/util/Counter.scala
index 872e830a..1c0b0203 100644
--- a/src/main/scala/Chisel/util/Counter.scala
+++ b/src/main/scala/chisel/util/Counter.scala
@@ -1,6 +1,8 @@
 // See LICENSE for license details.
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 /** A counter module
   * @param n number of counts before the counter resets (or one more than the
diff --git a/src/main/scala/Chisel/util/Decoupled.scala b/src/main/scala/chisel/util/Decoupled.scala
index 8e045855..89b0e39d 100644
--- a/src/main/scala/Chisel/util/Decoupled.scala
+++ b/src/main/scala/chisel/util/Decoupled.scala
@@ -3,7 +3,9 @@
 /** Wrappers for ready-valid (Decoupled) interfaces and associated circuit generators using them.
   */
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 /** An I/O Bundle with simple handshaking using valid and ready signals for data 'bits'*/
 class DecoupledIO[+T <: Data](gen: T) extends Bundle
@@ -108,7 +110,7 @@ class Queue[T <: Data](gen: T, val entries: Int,
 extends Module(override_reset=override_reset) {
   def this(gen: T, entries: Int, pipe: Boolean, flow: Boolean, _reset: Bool) =
     this(gen, entries, pipe, flow, Some(_reset))
-  
+
   val io = new QueueIO(gen, entries)
 
   val ram = Mem(entries, gen)
diff --git a/src/main/scala/Chisel/util/Enum.scala b/src/main/scala/chisel/util/Enum.scala
index 20057197..8babcd23 100644
--- a/src/main/scala/Chisel/util/Enum.scala
+++ b/src/main/scala/chisel/util/Enum.scala
@@ -3,7 +3,9 @@
 /** Enum generators, allowing circuit constants to have more meaningful names.
   */
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 object Enum {
   /** Returns a sequence of Bits subtypes with values from 0 until n. Helper method. */
diff --git a/src/main/scala/Chisel/ImplicitConversions.scala b/src/main/scala/chisel/util/ImplicitConversions.scala
index 6a230022..846c0cbd 100644
--- a/src/main/scala/Chisel/ImplicitConversions.scala
+++ b/src/main/scala/chisel/util/ImplicitConversions.scala
@@ -1,6 +1,8 @@
 // See LICENSE for license details.
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 object ImplicitConversions {
   implicit def intToUInt(x: Int): UInt = UInt(x)
diff --git a/src/main/scala/Chisel/util/LFSR.scala b/src/main/scala/chisel/util/LFSR.scala
index 839b1d1f..f70630bf 100644
--- a/src/main/scala/Chisel/util/LFSR.scala
+++ b/src/main/scala/chisel/util/LFSR.scala
@@ -3,7 +3,9 @@
 /** LFSRs in all shapes and sizes.
   */
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 // scalastyle:off magic.number
 /** linear feedback shift register
diff --git a/src/main/scala/Chisel/util/Lookup.scala b/src/main/scala/chisel/util/Lookup.scala
index 54922fc4..d32d9aec 100644
--- a/src/main/scala/Chisel/util/Lookup.scala
+++ b/src/main/scala/chisel/util/Lookup.scala
@@ -1,6 +1,8 @@
 // See LICENSE for license details.
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 object ListLookup {
   def apply[T <: Data](addr: UInt, default: List[T], mapping: Array[(BitPat, List[T])]): List[T] = {
diff --git a/src/main/scala/Chisel/util/Math.scala b/src/main/scala/chisel/util/Math.scala
index 5f8212d8..69464d15 100644
--- a/src/main/scala/Chisel/util/Math.scala
+++ b/src/main/scala/chisel/util/Math.scala
@@ -3,7 +3,9 @@
 /** Scala-land math helper functions, like logs.
   */
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 /** Compute the log2 rounded up with min value of 1 */
 object log2Up {
diff --git a/src/main/scala/Chisel/util/Mux.scala b/src/main/scala/chisel/util/Mux.scala
index 9d92321a..6f074a7e 100644
--- a/src/main/scala/Chisel/util/Mux.scala
+++ b/src/main/scala/chisel/util/Mux.scala
@@ -3,7 +3,10 @@
 /** Mux circuit generators.
   */
 
-package Chisel
+package chisel.util
+
+import chisel._
+import chisel.core.SeqUtils
 
 /** Builds a Mux tree out of the input signal vector using a one hot encoded
   select signal. Returns the output of the Mux tree.
diff --git a/src/main/scala/Chisel/util/OneHot.scala b/src/main/scala/chisel/util/OneHot.scala
index 73f27403..ef21c65d 100644
--- a/src/main/scala/Chisel/util/OneHot.scala
+++ b/src/main/scala/chisel/util/OneHot.scala
@@ -3,7 +3,9 @@
 /** Circuit generators for working with one-hot representations.
   */
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 /** Converts from One Hot Encoding to a UInt indicating which bit is active
   * This is the inverse of [[Chisel.UIntToOH UIntToOH]]*/
diff --git a/src/main/scala/Chisel/util/Reg.scala b/src/main/scala/chisel/util/Reg.scala
index 6584a4bf..1b40646d 100644
--- a/src/main/scala/Chisel/util/Reg.scala
+++ b/src/main/scala/chisel/util/Reg.scala
@@ -3,7 +3,9 @@
 /** Variations and helpers for registers.
   */
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 object RegNext {
 
diff --git a/src/main/scala/Chisel/util/TransitName.scala b/src/main/scala/chisel/util/TransitName.scala
index ec5a11cc..04e1995b 100644
--- a/src/main/scala/Chisel/util/TransitName.scala
+++ b/src/main/scala/chisel/util/TransitName.scala
@@ -1,5 +1,6 @@
-package Chisel
+package chisel.util
 
+import chisel._
 import internal.HasId
 
 object TransitName {
diff --git a/src/main/scala/Chisel/util/Valid.scala b/src/main/scala/chisel/util/Valid.scala
index 9e2202bb..56ac9abb 100644
--- a/src/main/scala/Chisel/util/Valid.scala
+++ b/src/main/scala/chisel/util/Valid.scala
@@ -3,7 +3,9 @@
 /** Wrappers for valid interfaces and associated circuit generators using them.
   */
 
-package Chisel
+package chisel.util
+
+import chisel._
 
 /** An I/O Bundle containing data and a signal determining if it is valid */
 class ValidIO[+T <: Data](gen2: T) extends Bundle
diff --git a/src/test/scala/chiselTests/Assert.scala b/src/test/scala/chiselTests/Assert.scala
index 24eb8b55..eb8617b2 100644
--- a/src/test/scala/chiselTests/Assert.scala
+++ b/src/test/scala/chiselTests/Assert.scala
@@ -3,8 +3,9 @@
 package chiselTests
 
 import org.scalatest._
-import Chisel._
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 class FailingAssertTester() extends BasicTester {
   assert(Bool(false))
diff --git a/src/test/scala/chiselTests/BitwiseOps.scala b/src/test/scala/chiselTests/BitwiseOps.scala
index 19aa956c..0c1d4d74 100644
--- a/src/test/scala/chiselTests/BitwiseOps.scala
+++ b/src/test/scala/chiselTests/BitwiseOps.scala
@@ -2,10 +2,10 @@
 
 package chiselTests
 
-import Chisel._
+import chisel._
 import org.scalatest._
 import org.scalatest.prop._
-import Chisel.testers.BasicTester
+import chisel.testers.BasicTester
 
 class BitwiseOpsTester(w: Int, _a: Int, _b: Int) extends BasicTester {
   val mask = (1 << w) - 1
diff --git a/src/test/scala/chiselTests/BlackBox.scala b/src/test/scala/chiselTests/BlackBox.scala
index ca94087c..b77550c1 100644
--- a/src/test/scala/chiselTests/BlackBox.scala
+++ b/src/test/scala/chiselTests/BlackBox.scala
@@ -4,8 +4,10 @@ package chiselTests
 
 import java.io.File
 import org.scalatest._
-import Chisel._
-import Chisel.testers.BasicTester
+
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 class BlackBoxInverter extends BlackBox {
   val io = new Bundle() {
diff --git a/src/test/scala/chiselTests/BundleWire.scala b/src/test/scala/chiselTests/BundleWire.scala
index d2e42fa9..36dbb365 100644
--- a/src/test/scala/chiselTests/BundleWire.scala
+++ b/src/test/scala/chiselTests/BundleWire.scala
@@ -1,10 +1,10 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
+import chisel._
 import org.scalatest._
 import org.scalatest.prop._
-import Chisel.testers.BasicTester
+import chisel.testers.BasicTester
 
 class Coord extends Bundle {
   val x = UInt(width = 32)
diff --git a/src/test/scala/chiselTests/ChiselSpec.scala b/src/test/scala/chiselTests/ChiselSpec.scala
index da68b0cb..9c66b0db 100644
--- a/src/test/scala/chiselTests/ChiselSpec.scala
+++ b/src/test/scala/chiselTests/ChiselSpec.scala
@@ -6,8 +6,8 @@ import java.io.File
 import org.scalatest._
 import org.scalatest.prop._
 import org.scalacheck._
-import Chisel._
-import Chisel.testers._
+import chisel._
+import chisel.testers._
 
 /** Common utility functions for Chisel unit tests. */
 trait ChiselRunners extends Assertions {
diff --git a/src/test/scala/chiselTests/ComplexAssign.scala b/src/test/scala/chiselTests/ComplexAssign.scala
index d79a2625..53a6a67d 100644
--- a/src/test/scala/chiselTests/ComplexAssign.scala
+++ b/src/test/scala/chiselTests/ComplexAssign.scala
@@ -1,11 +1,13 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
+
 import org.scalatest._
 import org.scalatest.prop._
 
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 class Complex[T <: Data](val re: T, val im: T) extends Bundle {
   override def cloneType: this.type =
diff --git a/src/test/scala/chiselTests/Counter.scala b/src/test/scala/chiselTests/Counter.scala
index 07a76cdc..963c1c92 100644
--- a/src/test/scala/chiselTests/Counter.scala
+++ b/src/test/scala/chiselTests/Counter.scala
@@ -1,10 +1,13 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
+
 import org.scalatest._
 import org.scalatest.prop._
-import Chisel.testers.BasicTester
+
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 class CountTester(max: Int) extends BasicTester {
   val cnt = Counter(max)
diff --git a/src/test/scala/chiselTests/Decoder.scala b/src/test/scala/chiselTests/Decoder.scala
index e5cdfd07..33980955 100644
--- a/src/test/scala/chiselTests/Decoder.scala
+++ b/src/test/scala/chiselTests/Decoder.scala
@@ -1,11 +1,14 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
+
 import org.scalatest._
 import org.scalatest.prop._
 import org.scalacheck._
-import Chisel.testers.BasicTester
+
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 class Decoder(bitpats: List[String]) extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/DeqIOSpec.scala b/src/test/scala/chiselTests/DeqIOSpec.scala
index 8f7937ab..95160140 100644
--- a/src/test/scala/chiselTests/DeqIOSpec.scala
+++ b/src/test/scala/chiselTests/DeqIOSpec.scala
@@ -2,8 +2,9 @@
 
 package chiselTests
 
-import Chisel._
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 /**
   * Created by chick on 2/8/16.
diff --git a/src/test/scala/chiselTests/Direction.scala b/src/test/scala/chiselTests/Direction.scala
index dd2f6572..3ed543aa 100644
--- a/src/test/scala/chiselTests/Direction.scala
+++ b/src/test/scala/chiselTests/Direction.scala
@@ -2,10 +2,10 @@
 
 package chiselTests
 
-import Chisel._
+import chisel._
 import org.scalatest._
 import org.scalatest.prop._
-import Chisel.testers.BasicTester
+import chisel.testers.BasicTester
 
 class DirectionHaver extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/EnableShiftRegister.scala b/src/test/scala/chiselTests/EnableShiftRegister.scala
index 6600df2a..30fc2486 100644
--- a/src/test/scala/chiselTests/EnableShiftRegister.scala
+++ b/src/test/scala/chiselTests/EnableShiftRegister.scala
@@ -1,8 +1,8 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
 
 class EnableShiftRegister extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/GCD.scala b/src/test/scala/chiselTests/GCD.scala
index a1bfffda..77452db6 100644
--- a/src/test/scala/chiselTests/GCD.scala
+++ b/src/test/scala/chiselTests/GCD.scala
@@ -2,8 +2,8 @@
 
 package chiselTests
 
-import Chisel._
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
 import org.scalatest._
 import org.scalatest.prop._
 
diff --git a/src/test/scala/chiselTests/Harness.scala b/src/test/scala/chiselTests/Harness.scala
index bc838766..805e2de9 100644
--- a/src/test/scala/chiselTests/Harness.scala
+++ b/src/test/scala/chiselTests/Harness.scala
@@ -1,13 +1,14 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel.testers.BasicTester
+
+import chisel.testers.BasicTester
 import org.scalatest._
 import org.scalatest.prop._
 import java.io.File
 
 class HarnessSpec extends ChiselPropSpec
-  with Chisel.BackendCompilationUtilities {
+  with chisel.BackendCompilationUtilities {
 
   def makeTrivialVerilog: (File => File) = makeHarness((prefix: String) => s"""
 module ${prefix};
diff --git a/src/test/scala/chiselTests/LFSR16.scala b/src/test/scala/chiselTests/LFSR16.scala
index ed76a296..b3e69884 100644
--- a/src/test/scala/chiselTests/LFSR16.scala
+++ b/src/test/scala/chiselTests/LFSR16.scala
@@ -1,8 +1,10 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
-import Chisel.testers.BasicTester
+
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 class LFSR16 extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/MemorySearch.scala b/src/test/scala/chiselTests/MemorySearch.scala
index 55b704a0..b48d2881 100644
--- a/src/test/scala/chiselTests/MemorySearch.scala
+++ b/src/test/scala/chiselTests/MemorySearch.scala
@@ -1,8 +1,9 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
-import Chisel.testers.BasicTester
+
+import chisel._
+import chisel.testers.BasicTester
 
 class MemorySearch extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/Module.scala b/src/test/scala/chiselTests/Module.scala
index 88ba795b..64b00fab 100644
--- a/src/test/scala/chiselTests/Module.scala
+++ b/src/test/scala/chiselTests/Module.scala
@@ -1,7 +1,8 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
+
+import chisel._
 
 class SimpleIO extends Bundle {
   val in  = UInt(INPUT,  32)
diff --git a/src/test/scala/chiselTests/MulLookup.scala b/src/test/scala/chiselTests/MulLookup.scala
index 49ba13c7..5e223f91 100644
--- a/src/test/scala/chiselTests/MulLookup.scala
+++ b/src/test/scala/chiselTests/MulLookup.scala
@@ -2,10 +2,10 @@
 
 package chiselTests
 
-import Chisel._
+import chisel._
 import org.scalatest._
 import org.scalatest.prop._
-import Chisel.testers.BasicTester
+import chisel.testers.BasicTester
 
 class MulLookup(val w: Int) extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/MultiAssign.scala b/src/test/scala/chiselTests/MultiAssign.scala
index 2f464123..152e6723 100644
--- a/src/test/scala/chiselTests/MultiAssign.scala
+++ b/src/test/scala/chiselTests/MultiAssign.scala
@@ -3,8 +3,10 @@
 package chiselTests
 
 import org.scalatest._
-import Chisel._
-import Chisel.testers.BasicTester
+
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 class LastAssignTester() extends BasicTester {
   val cnt = Counter(2)
diff --git a/src/test/scala/chiselTests/OptionBundle.scala b/src/test/scala/chiselTests/OptionBundle.scala
index c5a347e6..ab3b6860 100644
--- a/src/test/scala/chiselTests/OptionBundle.scala
+++ b/src/test/scala/chiselTests/OptionBundle.scala
@@ -3,8 +3,8 @@
 package chiselTests
 
 import org.scalatest._
-import Chisel._
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
 
 class OptionBundle(hasIn: Boolean) extends Bundle {
   val in = if (hasIn) {
diff --git a/src/test/scala/chiselTests/Padding.scala b/src/test/scala/chiselTests/Padding.scala
index 999b7d36..03496649 100644
--- a/src/test/scala/chiselTests/Padding.scala
+++ b/src/test/scala/chiselTests/Padding.scala
@@ -1,7 +1,8 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
+
+import chisel._
 
 class Padder extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/ParameterizedModule.scala b/src/test/scala/chiselTests/ParameterizedModule.scala
index 35e3ba78..e2629224 100644
--- a/src/test/scala/chiselTests/ParameterizedModule.scala
+++ b/src/test/scala/chiselTests/ParameterizedModule.scala
@@ -3,8 +3,8 @@
 package chiselTests
 
 import org.scalatest._
-import Chisel._
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
 
 class ParameterizedModule(invert: Boolean) extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/Printf.scala b/src/test/scala/chiselTests/Printf.scala
index eb8b4b25..b5e1e66e 100644
--- a/src/test/scala/chiselTests/Printf.scala
+++ b/src/test/scala/chiselTests/Printf.scala
@@ -3,8 +3,8 @@
 package chiselTests
 
 import org.scalatest._
-import Chisel._
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
 
 class SinglePrintfTester() extends BasicTester {
   val x = UInt(254)
diff --git a/src/test/scala/chiselTests/Reg.scala b/src/test/scala/chiselTests/Reg.scala
index f2620d88..8954c3ef 100644
--- a/src/test/scala/chiselTests/Reg.scala
+++ b/src/test/scala/chiselTests/Reg.scala
@@ -3,8 +3,8 @@
 package chiselTests
 
 import org.scalatest._
-import Chisel._
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
 
 class RegSpec extends ChiselFlatSpec {
   "A Reg" should "throw an exception if not given any parameters" in {
diff --git a/src/test/scala/chiselTests/Risc.scala b/src/test/scala/chiselTests/Risc.scala
index 3daa5bd2..741e9896 100644
--- a/src/test/scala/chiselTests/Risc.scala
+++ b/src/test/scala/chiselTests/Risc.scala
@@ -1,7 +1,9 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
+
+import chisel._
+import chisel.util._
 
 class Risc extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/SIntOps.scala b/src/test/scala/chiselTests/SIntOps.scala
index 0835fb4d..07111af6 100644
--- a/src/test/scala/chiselTests/SIntOps.scala
+++ b/src/test/scala/chiselTests/SIntOps.scala
@@ -1,8 +1,9 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
-import Chisel.testers.BasicTester
+
+import chisel._
+import chisel.testers.BasicTester
 
 class SIntOps extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/Stack.scala b/src/test/scala/chiselTests/Stack.scala
index ac799c8a..0ce228de 100644
--- a/src/test/scala/chiselTests/Stack.scala
+++ b/src/test/scala/chiselTests/Stack.scala
@@ -1,8 +1,11 @@
 // See LICENSE for license details.
 
 package chiselTests
+
 import scala.collection.mutable.Stack
-import Chisel._
+
+import chisel._
+import chisel.util._
 
 class ChiselStack(val depth: Int) extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/Stop.scala b/src/test/scala/chiselTests/Stop.scala
index 878f090c..d57eb7c6 100644
--- a/src/test/scala/chiselTests/Stop.scala
+++ b/src/test/scala/chiselTests/Stop.scala
@@ -3,8 +3,8 @@
 package chiselTests
 
 import org.scalatest._
-import Chisel._
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
 
 class StopTester() extends BasicTester {
   stop()
diff --git a/src/test/scala/chiselTests/Tbl.scala b/src/test/scala/chiselTests/Tbl.scala
index c79eb8a4..2049d8bb 100644
--- a/src/test/scala/chiselTests/Tbl.scala
+++ b/src/test/scala/chiselTests/Tbl.scala
@@ -2,10 +2,12 @@
 
 package chiselTests
 
-import Chisel._
 import org.scalatest._
 import org.scalatest.prop._
-import Chisel.testers.BasicTester
+
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 class Tbl(w: Int, n: Int) extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/TesterDriverSpec.scala b/src/test/scala/chiselTests/TesterDriverSpec.scala
index 3c57daae..50290fab 100644
--- a/src/test/scala/chiselTests/TesterDriverSpec.scala
+++ b/src/test/scala/chiselTests/TesterDriverSpec.scala
@@ -2,8 +2,9 @@
 
 package chiselTests
 
-import Chisel._
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 /** Extend BasicTester with a simple circuit and finish method.  TesterDriver will call the
   * finish method after the FinishTester's constructor has completed, which will alter the
diff --git a/src/test/scala/chiselTests/UIntOps.scala b/src/test/scala/chiselTests/UIntOps.scala
index bb0b0f06..8b2a31fd 100644
--- a/src/test/scala/chiselTests/UIntOps.scala
+++ b/src/test/scala/chiselTests/UIntOps.scala
@@ -1,9 +1,10 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
+
+import chisel._
 import org.scalatest._
-import Chisel.testers.BasicTester
+import chisel.testers.BasicTester
 
 class UIntOps extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/Vec.scala b/src/test/scala/chiselTests/Vec.scala
index 943d9e4b..35a0c8bc 100644
--- a/src/test/scala/chiselTests/Vec.scala
+++ b/src/test/scala/chiselTests/Vec.scala
@@ -2,10 +2,12 @@
 
 package chiselTests
 
-import Chisel._
 import org.scalatest._
 import org.scalatest.prop._
-import Chisel.testers.BasicTester
+
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 class ValueTester(w: Int, values: List[Int]) extends BasicTester {
   val v = Vec(values.map(UInt(_, width = w))) // TODO: does this need a Wire? Why no error?
diff --git a/src/test/scala/chiselTests/VectorPacketIO.scala b/src/test/scala/chiselTests/VectorPacketIO.scala
index 99ec66a6..a1282071 100644
--- a/src/test/scala/chiselTests/VectorPacketIO.scala
+++ b/src/test/scala/chiselTests/VectorPacketIO.scala
@@ -2,8 +2,9 @@
 
 package chiselTests
 
-import Chisel._
-import Chisel.testers.BasicTester
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 /**
   * This test used to fail when assignment statements were
diff --git a/src/test/scala/chiselTests/VendingMachine.scala b/src/test/scala/chiselTests/VendingMachine.scala
index 012fc493..0d621e6a 100644
--- a/src/test/scala/chiselTests/VendingMachine.scala
+++ b/src/test/scala/chiselTests/VendingMachine.scala
@@ -1,7 +1,9 @@
 // See LICENSE for license details.
 
 package chiselTests
-import Chisel._
+
+import chisel._
+import chisel.util._
 
 class VendingMachine extends Module {
   val io = new Bundle {
diff --git a/src/test/scala/chiselTests/When.scala b/src/test/scala/chiselTests/When.scala
index a6572706..1c9c3bc5 100644
--- a/src/test/scala/chiselTests/When.scala
+++ b/src/test/scala/chiselTests/When.scala
@@ -3,8 +3,10 @@
 package chiselTests
 
 import org.scalatest._
-import Chisel._
-import Chisel.testers.BasicTester
+
+import chisel._
+import chisel.testers.BasicTester
+import chisel.util._
 
 class WhenTester() extends BasicTester {
   val cnt = Counter(4)