Initial commit

src/test/scala/gcd/GCDSpec.scala

@@ -0,0 +1,52 @@
+// See README.md for license details.
+
+package gcd
+
+import chisel3._
+import chiseltest._
+import org.scalatest.freespec.AnyFreeSpec
+import chisel3.experimental.BundleLiterals._
+
+/**
+  * This is a trivial example of how to run this Specification
+  * From within sbt use:
+  * {{{
+  * testOnly gcd.GcdDecoupledTester
+  * }}}
+  * From a terminal shell use:
+  * {{{
+  * sbt 'testOnly gcd.GcdDecoupledTester'
+  * }}}
+  */
+class GCDSpec extends AnyFreeSpec with ChiselScalatestTester {
+
+  "Gcd should calculate proper greatest common denominator" in {
+    test(new DecoupledGcd(16)) { dut =>
+      dut.input.initSource()
+      dut.input.setSourceClock(dut.clock)
+      dut.output.initSink()
+      dut.output.setSinkClock(dut.clock)
+
+      val testValues = for { x <- 0 to 10; y <- 0 to 10} yield (x, y)
+      val inputSeq = testValues.map { case (x, y) => (new GcdInputBundle(16)).Lit(_.value1 -> x.U, _.value2 -> y.U) }
+      val resultSeq = testValues.map { case (x, y) =>
+        (new GcdOutputBundle(16)).Lit(_.value1 -> x.U, _.value2 -> y.U, _.gcd -> BigInt(x).gcd(BigInt(y)).U)
+      }
+
+      fork {
+        // push inputs into the calculator, stall for 11 cycles one third of the way
+        val (seq1, seq2) = inputSeq.splitAt(resultSeq.length / 3)
+        dut.input.enqueueSeq(seq1)
+        dut.clock.step(11)
+        dut.input.enqueueSeq(seq2)
+      }.fork {
+        // retrieve computations from the calculator, stall for 10 cycles one half of the way
+        val (seq1, seq2) = resultSeq.splitAt(resultSeq.length / 2)
+        dut.output.expectDequeueSeq(seq1)
+        dut.clock.step(10)
+        dut.output.expectDequeueSeq(seq2)
+      }.join()
+
+    }
+  }
+}