core.TwoStageQuarterRound: add

src/main/scala/uk/ac/soton/ecs/can/core/TwoStageQuarterRound.scala

+// SPDX-FileCopyrightText: 2021 Minyong Li <ml10g20@soton.ac.uk>
+// SPDX-License-Identifier: CERN-OHL-W-2.0
+
+package uk.ac.soton.ecs.can.core
+
+import chisel3._
+
+class TwoStageQuarterRound extends BaseQuarterRound {
+  private val a0 = in(0)
+  private val b0 = in(1)
+  private val c0 = in(2)
+  private val d0 = in(3)
+
+  private val a1 = a0 + b0
+  private val d1 = rotateLeft(d0 ^ a1, 16)
+  private val c1 = c0 + d1
+  private val b1 = rotateLeft(b0 ^ c1, 12)
+
+  private val reg = Reg(Vec(4, UInt(32.W)))
+  reg(0) := a1
+  reg(1) := b1
+  reg(2) := c1
+  reg(3) := d1
+
+  private val a2 = reg(0) + reg(1)
+  private val d2 = rotateLeft(reg(3) ^ a2, 8)
+  private val c2 = reg(2) + d2
+  private val b2 = rotateLeft(reg(1) ^ c2, 7)
+
+  out(0) := a2
+  out(1) := b2
+  out(2) := c2
+  out(3) := d2
+}