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authorducky2016-09-22 15:21:48 -0700
committerducky2016-09-22 15:21:48 -0700
commitdecb2ee0f0bb8223f0b2b067b88ed90b71473a28 (patch)
tree459cd428fd78b2f5d15aa1e841c15f1ba17af154 /src/main/scala/chisel3/util/Bitwise.scala
parent6eb00023fcc3ad77b98e51971f6e193ea506b9cc (diff)
Update rest of docs
Diffstat (limited to 'src/main/scala/chisel3/util/Bitwise.scala')
-rw-r--r--src/main/scala/chisel3/util/Bitwise.scala26
1 files changed, 18 insertions, 8 deletions
diff --git a/src/main/scala/chisel3/util/Bitwise.scala b/src/main/scala/chisel3/util/Bitwise.scala
index 6451ab14..7d5ffe09 100644
--- a/src/main/scala/chisel3/util/Bitwise.scala
+++ b/src/main/scala/chisel3/util/Bitwise.scala
@@ -8,9 +8,18 @@ package chisel3.util
import chisel3._
import chisel3.core.SeqUtils
-object FillInterleaved
-{
+object FillInterleaved {
+ /** Creates n repetitions of each bit of x in order.
+ *
+ * Output data-equivalent to in(size(in)-1) (n times) ## ... ## in(1) (n times) ## in(0) (n times)
+ * For example, FillInterleaved(2, "b1000") === UInt("b11 00 00 00")
+ */
def apply(n: Int, in: UInt): UInt = apply(n, in.toBools)
+
+ /** Creates n repetitions of each bit of x in order.
+ *
+ * Output data-equivalent to in(size(in)-1) (n times) ## ... ## in(1) (n times) ## in(0) (n times)
+ */
def apply(n: Int, in: Seq[Bool]): UInt = Cat(in.map(Fill(n, _)).reverse)
}
@@ -22,9 +31,11 @@ object PopCount
def apply(in: Bits): UInt = apply((0 until in.getWidth).map(in(_)))
}
-/** Fill fans out a UInt to multiple copies */
object Fill {
- /** Fan out x n times */
+ /** Create n repetitions of x using a tree fanout topology.
+ *
+ * Output data-equivalent to x ## x ## ... ## x (n repetitions).
+ */
def apply(n: Int, x: UInt): UInt = {
n match {
case 0 => UInt(width=0)
@@ -42,10 +53,7 @@ object Fill {
}
}
-/** Litte/big bit endian convertion: reverse the order of the bits in a UInt.
-*/
-object Reverse
-{
+object Reverse {
private def doit(in: UInt, length: Int): UInt = {
if (length == 1) {
in
@@ -65,5 +73,7 @@ object Reverse
Cat(doit(in(half-1,0), half), doit(in(length-1,half), length-half))
}
}
+ /** Returns the input in bit-reversed order. Useful for little/big-endian conversion.
+ */
def apply(in: UInt): UInt = doit(in, in.getWidth)
}