diff options
Diffstat (limited to 'src/main/scala/chisel3/util/Counter.scala')
| -rw-r--r-- | src/main/scala/chisel3/util/Counter.scala | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/src/main/scala/chisel3/util/Counter.scala b/src/main/scala/chisel3/util/Counter.scala index f6f99f67..dbfd5bdd 100644 --- a/src/main/scala/chisel3/util/Counter.scala +++ b/src/main/scala/chisel3/util/Counter.scala @@ -5,10 +5,13 @@ package chisel3.util import chisel3._ import chisel3.internal.naming.chiselName // can't use chisel3_ version because of compile order -/** A counter module +/** Used to generate an inline (logic directly in the containing Module, no internal Module is created) + * hardware counter. * * Typically instantiated with apply methods in [[Counter$ object Counter]] * + * Does not create a new Chisel Module + * * @example {{{ * val countOn = true.B // increment counter every clock cycle * val (counterValue, counterWrap) = Counter(countOn, 4) @@ -59,6 +62,11 @@ object Counter @chiselName def apply(cond: Bool, n: Int): (UInt, Bool) = { val c = new Counter(n) + // Note this use of var is generally frowned upon! Don't use this as an example. + // This is done because we wanted the hardware generated by c.inc() to be wrapped + // in a when statement, but still needed to refer to the final value returned by + // c.inc() so we could return cond && wrap. Unless you really, really know what + // you are doing, IGNORE THIS CODE!!!!! var wrap: Bool = null when (cond) { wrap = c.inc() } (c.value, cond && wrap) |