diff --git a/libraries/mbed/targets/hal/TARGET_Atmel/TARGET_SAM21/TARGET_SAMR21G18A/device.h b/libraries/mbed/targets/hal/TARGET_Atmel/TARGET_SAM21/TARGET_SAMR21G18A/device.h
index b8f9cf55d6..cb86101f69 100644
--- a/libraries/mbed/targets/hal/TARGET_Atmel/TARGET_SAM21/TARGET_SAMR21G18A/device.h
+++ b/libraries/mbed/targets/hal/TARGET_Atmel/TARGET_SAM21/TARGET_SAMR21G18A/device.h
@@ -20,7 +20,7 @@
 #define DEVICE_PORTOUT          1
 #define DEVICE_PORTINOUT        1
 
-#define DEVICE_INTERRUPTIN      0
+#define DEVICE_INTERRUPTIN      1
 
 #define DEVICE_ANALOGIN         1
 #define DEVICE_ANALOGOUT        0
diff --git a/libraries/mbed/targets/hal/TARGET_Atmel/TARGET_SAM21/gpio_irq_api.c b/libraries/mbed/targets/hal/TARGET_Atmel/TARGET_SAM21/gpio_irq_api.c
new file mode 100644
index 0000000000..e593862e5c
--- /dev/null
+++ b/libraries/mbed/targets/hal/TARGET_Atmel/TARGET_SAM21/gpio_irq_api.c
@@ -0,0 +1,142 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * 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.
+ */
+#include <stddef.h>
+#include "cmsis.h"
+
+#include "gpio_irq_api.h"
+#include "gpio_api.h"
+#include "mbed_error.h"
+#include "extint.h"
+
+#define CHANNEL_NUM 15
+static uint32_t channel_ids[CHANNEL_NUM] = {0};
+static gpio_irq_handler irq_handler;
+
+int get_extint_channel(PinName pin)
+{
+    switch (pin) {
+        case PA16:
+        case PB00:
+        case PB16:
+        case PA00:
+            return 0;
+
+        case PA17:
+        case PB17:
+        case PA01:
+            return 1;
+
+        case PA18:
+        case PA02:
+            return 2;
+
+        case PA19:
+        case PB03:
+            return 3;
+
+        case PA04:
+        case PA20:
+            return 4;
+
+        case PA05:
+            return 5;
+
+        case PA06:
+        case PA22:
+        case PB22:
+            return 6;
+
+        case PA07:
+        case PA23:
+        case PB28:
+            return 7;
+
+        case PA28:
+        case PB08:
+            return 8;
+
+        case PA09:
+        case PB09:
+            return 9;
+
+        case PA10:
+        case PA30:
+            return 10;
+
+        case PA11:
+        case PA31:
+            return 11;
+
+        case PA12:
+        case PA24:
+            return 12;
+
+        case PA13:
+        case PA25:
+            return 13;
+
+        case PB14:
+        case PB30:
+        case PA14:
+            return 14;
+
+        case PA15:
+        case PA27:
+        case PB15:
+        case PB31:
+            return 15;
+
+        default :
+            return 0xFF;
+    }
+}
+
+int gpio_irq_init(gpio_irq_t *obj, PinName pin, gpio_irq_handler handler, uint32_t id)
+{
+    struct extint_chan_conf config_extint_chan;
+    int int_channel = 0;
+    if (pin == NC)
+        return -1;
+
+    irq_handler = handler;
+
+    extint_chan_get_config_defaults(&config_extint_chan);
+    config_extint_chan.gpio_pin           = (uint32_t)pin;
+    config_extint_chan.gpio_pin_mux       = 0;   // mux setting for ext int is 0
+    config_extint_chan.gpio_pin_pull      = EXTINT_PULL_UP;
+    config_extint_chan.detection_criteria = EXTINT_DETECT_BOTH;
+    int_channel = get_extint_channel(pin);
+    if (int_channel != 0xFF) {
+        extint_chan_set_config(int_channel, &config_extint_chan);
+    }
+}
+
+void gpio_irq_free(gpio_irq_t *obj)
+{
+}
+
+void gpio_irq_set(gpio_irq_t *obj, gpio_irq_event event, uint32_t enable)
+{
+
+}
+
+void gpio_irq_enable(gpio_irq_t *obj)
+{
+}
+
+void gpio_irq_disable(gpio_irq_t *obj)
+{
+}