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| author | Jim Lawson | 2016-09-23 08:19:43 -0700 |
|---|---|---|
| committer | GitHub | 2016-09-23 08:19:43 -0700 |
| commit | 785620b1403d827986bf60c2a001d8d6f71eed72 (patch) | |
| tree | 1c1a0b14b041e544da3ff8176aba200604a131b3 /src/main/scala/chisel3/util/OneHot.scala | |
| parent | b18e98ba2d058c7dd24f96f005486b70c856aeca (diff) | |
| parent | decb2ee0f0bb8223f0b2b067b88ed90b71473a28 (diff) | |
Merge pull request #291 from ucb-bar/utilscaladocs
Scaladocs for utils
Diffstat (limited to 'src/main/scala/chisel3/util/OneHot.scala')
| -rw-r--r-- | src/main/scala/chisel3/util/OneHot.scala | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/src/main/scala/chisel3/util/OneHot.scala b/src/main/scala/chisel3/util/OneHot.scala index 7e04a8d7..53ba8c3d 100644 --- a/src/main/scala/chisel3/util/OneHot.scala +++ b/src/main/scala/chisel3/util/OneHot.scala @@ -7,8 +7,12 @@ package chisel3.util import chisel3._ -/** Converts from One Hot Encoding to a UInt indicating which bit is active - * This is the inverse of [[Chisel.UIntToOH UIntToOH]]*/ +/** Returns the bit position of the sole high bit of the input bitvector. + * + * Inverse operation of [[UIntToOH]]. + * + * @note assumes exactly one high bit, results undefined otherwise + */ object OHToUInt { def apply(in: Seq[Bool]): UInt = apply(Cat(in.reverse), in.size) def apply(in: Vec[Bool]): UInt = apply(in.asUInt, in.size) @@ -26,9 +30,9 @@ object OHToUInt { } } -/** @return the bit position of the trailing 1 in the input vector - * with the assumption that multiple bits of the input bit vector can be set - * @example {{{ data_out := PriorityEncoder(data_in) }}} +/** Returns the bit position of the least-significant high bit of the input bitvector. + * + * Multiple bits may be high in the input. */ object PriorityEncoder { def apply(in: Seq[Bool]): UInt = PriorityMux(in, (0 until in.size).map(UInt(_))) @@ -37,8 +41,7 @@ object PriorityEncoder { /** Returns the one hot encoding of the input UInt. */ -object UIntToOH -{ +object UIntToOH { def apply(in: UInt, width: Int = -1): UInt = if (width == -1) { UInt(1) << in @@ -47,11 +50,10 @@ object UIntToOH } } -/** Returns a bit vector in which only the least-significant 1 bit in - the input vector, if any, is set. +/** Returns a bit vector in which only the least-significant 1 bit in the input vector, if any, + * is set. */ -object PriorityEncoderOH -{ +object PriorityEncoderOH { private def encode(in: Seq[Bool]): UInt = { val outs = Seq.tabulate(in.size)(i => UInt(BigInt(1) << i, in.size)) PriorityMux(in :+ Bool(true), outs :+ UInt(0, in.size)) |
