single lane scrambler

Author: pawat-unj

src/main/scala/Scrambler.scala

@@ -0,0 +1,25 @@
+package edu.berkeley.cs.ucie.digital
+
+import chisel3._
+import chisel3.util._
+import chisel3.util.random._
+
+// 
+
+class Scrambler extends Module {
+  val io = IO(new Bundle {
+    val L0_in = Input(UInt(16.W))
+    val valid = Input(Bool())
+    val rst = Input(Bool())
+    val L0_out = Output(UInt(16.W))
+  })
+  val L0_LFSR = Module(new FibonacciLFSR(23, Set(23,21,18,15,7,2,1), Some(BigInt(1949628)), XOR, 16, false))
+  L0_LFSR.io.increment := io.valid
+  L0_LFSR.io.seed.bits := VecInit(1949628.U(23.W).asBools)
+  L0_LFSR.io.seed.valid := (reset.asBool || io.rst)
+  
+  val L0_LFSR_result = L0_LFSR.io.out
+  printf(cf"$L0_LFSR_result.asUInt")
+  io.L0_out :=  L0_LFSR_result.asUInt ^ io.L0_in
+}
+

src/test/scala/Scrambler.scala

@@ -0,0 +1,25 @@
+package edu.berkeley.cs.ucie.digital
+
+import chisel3._
+import chiseltest._
+import org.scalatest.funspec.AnyFunSpec
+
+class ScramblerTest extends AnyFunSpec with ChiselScalatestTester {
+  describe("Scrambler") {
+    it("should scramble one lane") {
+      test(new Scrambler()) { c =>
+        c.io.rst.poke(true.B)
+        c.clock.step()
+        c.clock.step()
+        c.io.rst.poke(false.B)
+        c.clock.step()
+        c.io.valid.poke(true.B)
+        c.io.L0_in.poke(9628)
+        c.io.L0_out.expect(39456)
+        c.clock.step()
+        c.io.L0_in.poke(13458)
+        c.io.L0_out.expect(48271)
+      }
+    }
+  }
+}