diff options
| author | Jim Lawson | 2016-07-06 10:01:23 -0700 |
|---|---|---|
| committer | Jim Lawson | 2016-07-18 15:17:56 -0700 |
| commit | c5f9ea3133ef363ff8944e17d94fea79767b6bed (patch) | |
| tree | cc80a6df1eb58f0feaf9f138eb7fe261ccda4ea2 /chiselFrontend/src/main/scala/chisel3/core/Data.scala | |
| parent | 53813f61b7dfe246d214ab966739d01c65c8ecb0 (diff) | |
Rename "Chisel" to "chisel3" (only git mv).
Diffstat (limited to 'chiselFrontend/src/main/scala/chisel3/core/Data.scala')
| -rw-r--r-- | chiselFrontend/src/main/scala/chisel3/core/Data.scala | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/chiselFrontend/src/main/scala/chisel3/core/Data.scala b/chiselFrontend/src/main/scala/chisel3/core/Data.scala new file mode 100644 index 00000000..d16843f7 --- /dev/null +++ b/chiselFrontend/src/main/scala/chisel3/core/Data.scala @@ -0,0 +1,161 @@ +// See LICENSE for license details. + +package Chisel + +import scala.language.experimental.macros + +import internal._ +import internal.Builder.pushCommand +import internal.firrtl._ +import internal.sourceinfo.{SourceInfo, DeprecatedSourceInfo, UnlocatableSourceInfo, WireTransform, SourceInfoTransform} + +sealed abstract class Direction(name: String) { + override def toString: String = name + def flip: Direction +} +object INPUT extends Direction("input") { override def flip: Direction = OUTPUT } +object OUTPUT extends Direction("output") { override def flip: Direction = INPUT } +object NO_DIR extends Direction("?") { override def flip: Direction = NO_DIR } + +@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 +} + +/** Mixing in this trait flips the direction of an Aggregate. */ +trait Flipped extends Data { + this.overrideDirection(_.flip, !_) +} + +/** This forms the root of the type system for wire data types. The data value + * must be representable as some number (need not be known at Chisel compile + * time) of bits, and must have methods to pack / unpack structured data to / + * from bits. + */ +abstract class Data(dirArg: Direction) extends HasId { + def dir: Direction = dirVar + + // Sucks this is mutable state, but cloneType doesn't take a Direction arg + private var isFlipVar = dirArg == INPUT + private var dirVar = dirArg + private[Chisel] def isFlip = isFlipVar + + private[Chisel] def overrideDirection(newDir: Direction => Direction, + newFlip: Boolean => Boolean): this.type = { + this.isFlipVar = newFlip(this.isFlipVar) + for (field <- this.flatten) + (field: Data).dirVar = newDir((field: Data).dirVar) + this + } + def asInput: this.type = cloneType.overrideDirection(_ => INPUT, _ => true) + def asOutput: this.type = cloneType.overrideDirection(_ => OUTPUT, _ => false) + def flip(): this.type = cloneType.overrideDirection(_.flip, !_) + + private[Chisel] def badConnect(that: Data)(implicit sourceInfo: SourceInfo): Unit = + throwException(s"cannot connect ${this} and ${that}") + private[Chisel] def connect(that: Data)(implicit sourceInfo: SourceInfo): Unit = + pushCommand(Connect(sourceInfo, this.lref, that.ref)) + private[Chisel] def bulkConnect(that: Data)(implicit sourceInfo: SourceInfo): Unit = + pushCommand(BulkConnect(sourceInfo, this.lref, that.lref)) + private[Chisel] def lref: Node = Node(this) + private[Chisel] def ref: Arg = if (isLit) litArg.get else lref + private[Chisel] def cloneTypeWidth(width: Width): this.type + private[Chisel] def toType: String + + def := (that: Data)(implicit sourceInfo: SourceInfo): Unit = this badConnect that + + def <> (that: Data)(implicit sourceInfo: SourceInfo): Unit = this badConnect that + + def cloneType: this.type + def litArg(): Option[LitArg] = None + def litValue(): BigInt = litArg.get.num + def isLit(): Boolean = litArg.isDefined + + def width: Width + final def getWidth: Int = width.get + + // While this being in the Data API doesn't really make sense (should be in + // Aggregate, right?) this is because of an implementation limitation: + // cloneWithDirection, which is private and defined here, needs flatten to + // set element directionality. + // Related: directionality is mutable state. A possible solution for both is + // to define directionality relative to the container, but these parent links + // currently don't exist (while this information may be available during + // FIRRTL emission, it would break directionality querying from Chisel, which + // does get used). + private[Chisel] def flatten: IndexedSeq[Bits] + + /** Creates an new instance of this type, unpacking the input Bits into + * structured data. + * + * This performs the inverse operation of toBits. + * + * @note does NOT assign to the object this is called on, instead creates + * and returns a NEW object (useful in a clone-and-assign scenario) + * @note does NOT check bit widths, may drop bits during assignment + * @note what fromBits assigs to must have known widths + */ + def fromBits(that: Bits): this.type = macro SourceInfoTransform.thatArg + + def do_fromBits(that: Bits)(implicit sourceInfo: SourceInfo): this.type = { + var i = 0 + val wire = Wire(this.cloneType) + val bits = + if (that.width.known && that.width.get >= wire.width.get) { + that + } else { + Wire(that.cloneTypeWidth(wire.width), init = that) + } + for (x <- wire.flatten) { + x := bits(i + x.getWidth-1, i) + i += x.getWidth + } + wire.asInstanceOf[this.type] + } + + /** Packs the value of this object as plain Bits. + * + * This performs the inverse operation of fromBits(Bits). + */ + @deprecated("Use asBits, which makes the reinterpret cast more explicit and actually returns Bits", "chisel3") + def toBits(): UInt = SeqUtils.do_asUInt(this.flatten)(DeprecatedSourceInfo) +} + +object Wire { + def apply[T <: Data](t: T): T = macro WireTransform.apply[T] + + // No source info since Scala macros don't yet support named / default arguments. + def apply[T <: Data](dummy: Int = 0, init: T): T = + do_apply(null.asInstanceOf[T], init)(UnlocatableSourceInfo) + + // No source info since Scala macros don't yet support named / default arguments. + def apply[T <: Data](t: T, init: T): T = + do_apply(t, init)(UnlocatableSourceInfo) + + def do_apply[T <: Data](t: T, init: T)(implicit sourceInfo: SourceInfo): T = { + val x = Reg.makeType(t, null.asInstanceOf[T], init) + pushCommand(DefWire(sourceInfo, x)) + pushCommand(DefInvalid(sourceInfo, x.ref)) + if (init != null) { + x := init + } + x + } +} + +object Clock { + def apply(dir: Direction = NO_DIR): Clock = new Clock(dir) +} + +// TODO: Document this. +sealed class Clock(dirArg: Direction) extends Element(dirArg, Width(1)) { + def cloneType: this.type = Clock(dirArg).asInstanceOf[this.type] + private[Chisel] override def flatten: IndexedSeq[Bits] = IndexedSeq() + private[Chisel] def cloneTypeWidth(width: Width): this.type = cloneType + private[Chisel] def toType = "Clock" + + override def := (that: Data)(implicit sourceInfo: SourceInfo): Unit = that match { + case _: Clock => this connect that + case _ => this badConnect that + } +} |
