Break out Utils.scala into smaller portions

1 files changed, 35 insertions, 0 deletions

diff --git a/src/main/scala/Chisel/util/Counter.scala b/src/main/scala/Chisel/util/Counter.scala
new file mode 100644
index 00000000..e4a8e95b
--- /dev/null
+++ b/src/main/scala/Chisel/util/Counter.scala
@@ -0,0 +1,35 @@
+// See LICENSE for license details.
+
+package Chisel
+
+/** A counter module
+  * @param n The maximum value of the counter, does not have to be power of 2
+  */
+class Counter(val n: Int) {
+  val value = if (n == 1) UInt(0) else Reg(init=UInt(0, log2Up(n)))
+  def inc(): Bool = {
+    if (n == 1) {
+      Bool(true)
+    } else {
+      val wrap = value === UInt(n-1)
+      value := Mux(Bool(!isPow2(n)) && wrap, UInt(0), value + UInt(1))
+      wrap
+    }
+  }
+}
+
+/** Counter Object
+  * Example Usage:
+  * {{{ val countOn = Bool(true) // increment counter every clock cycle
+  * val myCounter = Counter(countOn, n)
+  * when ( myCounter.value === UInt(3) ) { ... } }}}*/
+object Counter
+{
+  def apply(n: Int): Counter = new Counter(n)
+  def apply(cond: Bool, n: Int): (UInt, Bool) = {
+    val c = new Counter(n)
+    var wrap: Bool = null
+    when (cond) { wrap = c.inc() }
+    (c.value, cond && wrap)
+  }
+}