[LICENSE] Add SPDX Identifier
diff --git a/verilog/dv/dummy_slave.v b/verilog/dv/dummy_slave.v
index add6694..4b12665 100644
--- a/verilog/dv/dummy_slave.v
+++ b/verilog/dv/dummy_slave.v
@@ -11,6 +11,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 `default_nettype none
 module dummy_slave(