From c5f9ea3133ef363ff8944e17d94fea79767b6bed Mon Sep 17 00:00:00 2001 From: Jim Lawson Date: Wed, 6 Jul 2016 10:01:23 -0700 Subject: Rename "Chisel" to "chisel3" (only git mv). --- src/main/scala/chisel3/util/CircuitMath.scala | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 src/main/scala/chisel3/util/CircuitMath.scala (limited to 'src/main/scala/chisel3/util/CircuitMath.scala') diff --git a/src/main/scala/chisel3/util/CircuitMath.scala b/src/main/scala/chisel3/util/CircuitMath.scala new file mode 100644 index 00000000..06cab903 --- /dev/null +++ b/src/main/scala/chisel3/util/CircuitMath.scala @@ -0,0 +1,26 @@ +// See LICENSE for license details. + +/** Circuit-land math operations. + */ + +package 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 + * @example + * {{{ data_out := Log2(data_in) }}} + * @note Truncation is used so Log2(UInt(12412)) = 13*/ +object Log2 { + /** Compute the Log2 on the least significant n bits of x */ + def apply(x: Bits, width: Int): UInt = { + if (width < 2) { + UInt(0) + } else if (width == 2) { + x(1) + } else { + Mux(x(width-1), UInt(width-1), apply(x, width-1)) + } + } + + def apply(x: Bits): UInt = apply(x, x.getWidth) +} -- cgit v1.2.3