diff --git a/src/main/scala/uk/ac/soton/ecs/can/core/DataMemory.scala b/src/main/scala/uk/ac/soton/ecs/can/core/DataMemory.scala
index ad0b08daf55d58d842201342e758ae68a0f9846e..979e0d6d74b98bd42524526ba598f53955ba96df 100644
--- a/src/main/scala/uk/ac/soton/ecs/can/core/DataMemory.scala
+++ b/src/main/scala/uk/ac/soton/ecs/can/core/DataMemory.scala
@@ -1,3 +1,6 @@
+// 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._
diff --git a/src/main/scala/uk/ac/soton/ecs/can/core/ProgramMemory.scala b/src/main/scala/uk/ac/soton/ecs/can/core/ProgramMemory.scala
index 59ace230e24d972b68e90f77c9135cad4befbc72..7f7dbd2e19ebd2ad0ab2ab04d1181af64576bd32 100644
--- a/src/main/scala/uk/ac/soton/ecs/can/core/ProgramMemory.scala
+++ b/src/main/scala/uk/ac/soton/ecs/can/core/ProgramMemory.scala
@@ -1,3 +1,6 @@
+// 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._
diff --git a/src/main/scala/uk/ac/soton/ecs/can/core/QuarterRound.scala b/src/main/scala/uk/ac/soton/ecs/can/core/QuarterRound.scala
index a60650d20343ddb6e9877a12b1dbab017448f04b..9efdf3247a7e256964a7d302b288d05650050084 100644
--- a/src/main/scala/uk/ac/soton/ecs/can/core/QuarterRound.scala
+++ b/src/main/scala/uk/ac/soton/ecs/can/core/QuarterRound.scala
@@ -1,3 +1,6 @@
+// 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._
diff --git a/src/test/scala/uk/ac/soton/ecs/can/core/DataMemoryTest.scala b/src/test/scala/uk/ac/soton/ecs/can/core/DataMemoryTest.scala
index 7b7d0dd8068b1edd7f74f9c341bc7b194851f507..3ea68b3e60cb252841c93bd850096ec174fa1411 100644
--- a/src/test/scala/uk/ac/soton/ecs/can/core/DataMemoryTest.scala
+++ b/src/test/scala/uk/ac/soton/ecs/can/core/DataMemoryTest.scala
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: 2021 Minyong Li <ml10g20@soton.ac.uk>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 package uk.ac.soton.ecs.can.core
 
 import org.scalatest._
diff --git a/src/test/scala/uk/ac/soton/ecs/can/core/ProgramMemoryTest.scala b/src/test/scala/uk/ac/soton/ecs/can/core/ProgramMemoryTest.scala
index 5138606024066d575768a97020958c498b19ecd8..6fce45214a4c4088e7427975fdc668925c91df23 100644
--- a/src/test/scala/uk/ac/soton/ecs/can/core/ProgramMemoryTest.scala
+++ b/src/test/scala/uk/ac/soton/ecs/can/core/ProgramMemoryTest.scala
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: 2021 Minyong Li <ml10g20@soton.ac.uk>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 package uk.ac.soton.ecs.can.core
 
 import org.scalatest._
diff --git a/src/test/scala/uk/ac/soton/ecs/can/core/QuarterRoundTest.scala b/src/test/scala/uk/ac/soton/ecs/can/core/QuarterRoundTest.scala
index 59f5c6dd7323e112b97810139a49b0afcae17a94..0cc37f7067b2d2d04dd05339a33bfaec813b952b 100644
--- a/src/test/scala/uk/ac/soton/ecs/can/core/QuarterRoundTest.scala
+++ b/src/test/scala/uk/ac/soton/ecs/can/core/QuarterRoundTest.scala
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: 2021 Minyong Li <ml10g20@soton.ac.uk>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 package uk.ac.soton.ecs.can.core
 
 import org.scalatest._