diff --git a/cell/api/u_cell_gpio.h b/cell/api/u_cell_gpio.h
index dd1a7934..a1af9b00 100644
--- a/cell/api/u_cell_gpio.h
+++ b/cell/api/u_cell_gpio.h
@@ -108,6 +108,8 @@ typedef enum {
  * the interface manual of your module for details.
  */
 typedef enum {
+    U_CELL_GPIO_SPECIAL_FUNCTION_OUTPUT = 0,
+    U_CELL_GPIO_SPECIAL_FUNCTION_INPUT = 1,
     U_CELL_GPIO_SPECIAL_FUNCTION_NETWORK_STATUS_INDICATION = 2,
     U_CELL_GPIO_SPECIAL_FUNCTION_EXTERNAL_GNSS_SUPPLY_ENABLE = 3,
     U_CELL_GPIO_SPECIAL_FUNCTION_EXTERNAL_GNSS_DATA_READY = 4,
@@ -123,22 +125,24 @@ typedef enum {
     U_CELL_GPIO_SPECIAL_FUNCTION_MASTER_CLOCK_GENERATION = 14,
     U_CELL_GPIO_SPECIAL_FUNCTION_UART_INTERFACE = 15,
     U_CELL_GPIO_SPECIAL_FUNCTION_WIFI_ENABLE = 16,
-    U_CELL_GPIO_SPECIAL_FUNCTION_RING_INDICATOR = 17,
-    U_CELL_GPIO_SPECIAL_FUNCTION_LAST_GASP = 18,
-    U_CELL_GPIO_SPECIAL_FUNCTION_EXTERNAL_GNSS_ANTENNA_OR_LNA_CONTROL = 19,
-    U_CELL_GPIO_SPECIAL_FUNCTION_TIME_PULSE_GNSS = 20,
-    U_CELL_GPIO_SPECIAL_FUNCTION_TIME_PULSE_OUTPUT = 21,
-    U_CELL_GPIO_SPECIAL_FUNCTION_TIME_STAMP_OF_EXTERNAL_INTERRUPT = 22,
-    U_CELL_GPIO_SPECIAL_FUNCTION_FAST_POWER_OFF = 23,
-    U_CELL_GPIO_SPECIAL_FUNCTION_LWM2M_PULSE = 24,
-    U_CELL_GPIO_SPECIAL_FUNCTION_HARDWARE_FLOW_CONTROL = 25,
-    U_CELL_GPIO_SPECIAL_FUNCTION_ANTENNA_DYNAMIC_TUNING = 26,
-    U_CELL_GPIO_SPECIAL_FUNCTION_EXTERNAL_GNSS_TIME_PULSE_INPUT = 27,
-    U_CELL_GPIO_SPECIAL_FUNCTION_EXTERNAL_GNSS_TIME_STAMP_OF_EXTERNAL_INTERRUPT = 28,
-    U_CELL_GPIO_SPECIAL_FUNCTION_DTR_POWER_SAVING = 29,
-    U_CELL_GPIO_SPECIAL_FUNCTION_32_KHZ_OUTPUT = 30,
-    U_CELL_GPIO_SPECIAL_FUNCTION_SAFE_MEMORY_AND_POWER_OFF = 31,
-    U_CELL_GPIO_SPECIAL_FUNCTION_UPSV_CONTROL = 32,
+    U_CELL_GPIO_SPECIAL_FUNCTION_INPUT_WITH_INTERRUPT = 17,
+    U_CELL_GPIO_SPECIAL_FUNCTION_RING_INDICATOR = 18,
+    U_CELL_GPIO_SPECIAL_FUNCTION_LAST_GASP = 19,
+    U_CELL_GPIO_SPECIAL_FUNCTION_EXTERNAL_GNSS_ANTENNA_OR_LNA_CONTROL = 20,
+    U_CELL_GPIO_SPECIAL_FUNCTION_TIME_PULSE_GNSS = 21,
+    U_CELL_GPIO_SPECIAL_FUNCTION_TIME_PULSE_OUTPUT = 22,
+    U_CELL_GPIO_SPECIAL_FUNCTION_TIME_STAMP_OF_EXTERNAL_INTERRUPT = 23,
+    U_CELL_GPIO_SPECIAL_FUNCTION_FAST_POWER_OFF = 24,
+    U_CELL_GPIO_SPECIAL_FUNCTION_LWM2M_PULSE = 25,
+    U_CELL_GPIO_SPECIAL_FUNCTION_HARDWARE_FLOW_CONTROL = 26,
+    U_CELL_GPIO_SPECIAL_FUNCTION_ANTENNA_DYNAMIC_TUNING = 27,
+    U_CELL_GPIO_SPECIAL_FUNCTION_EXTERNAL_GNSS_TIME_PULSE_INPUT = 28,
+    U_CELL_GPIO_SPECIAL_FUNCTION_EXTERNAL_GNSS_TIME_STAMP_OF_EXTERNAL_INTERRUPT = 29,
+    U_CELL_GPIO_SPECIAL_FUNCTION_DTR_POWER_SAVING = 30,
+    // GPIO MODE 31 is not supported.
+    U_CELL_GPIO_SPECIAL_FUNCTION_32_KHZ_OUTPUT = 32,
+    U_CELL_GPIO_SPECIAL_FUNCTION_SAFE_MEMORY_AND_POWER_OFF = 33,
+    U_CELL_GPIO_SPECIAL_FUNCTION_UPSV_CONTROL = 34,
     U_CELL_GPIO_SPECIAL_FUNCTION_PAD_DISABLED = 255
 } uCellGpioSpecialFunction_t;