diff --git a/demos/device/src/cdc_device_app.c b/demos/device/src/cdc_device_app.c
index 8059b938d..d8491d87b 100644
--- a/demos/device/src/cdc_device_app.c
+++ b/demos/device/src/cdc_device_app.c
@@ -139,7 +139,7 @@ tusb_error_t cdcd_serial_subtask(void)
   osal_semaphore_wait(sem_hdl, OSAL_TIMEOUT_WAIT_FOREVER, &error);
   (void) error; // suppress compiler's warnings
 
-  if ( tud_configured(0) )
+  if ( tud_mounted(0) )
   {
     // echo back data in the fifo
     if ( !tud_cdc_busy(0, CDC_PIPE_DATA_IN) )
diff --git a/demos/device/src/keyboard_device_app.c b/demos/device/src/keyboard_device_app.c
index 14f0611fa..61e42f99d 100644
--- a/demos/device/src/keyboard_device_app.c
+++ b/demos/device/src/keyboard_device_app.c
@@ -126,7 +126,7 @@ tusb_error_t keyboard_device_subtask(void)
 
   osal_task_delay(50);
 
-  if ( tud_configured(0) && !tud_hid_keyboard_busy(0) )
+  if ( tud_mounted(0) && !tud_hid_keyboard_busy(0) )
   {
     static uint32_t button_mask = 0;
     uint32_t new_button_mask = board_buttons();
diff --git a/tinyusb/class/cdc_device.c b/tinyusb/class/cdc_device.c
index 6b64e56a7..455c04339 100644
--- a/tinyusb/class/cdc_device.c
+++ b/tinyusb/class/cdc_device.c
@@ -66,7 +66,7 @@ STATIC_VAR cdcd_data_t cdcd_data[CONTROLLER_DEVICE_NUMBER];
 
 static tusb_error_t cdcd_xfer(uint8_t coreid,  cdc_pipeid_t pipeid, void * p_buffer, uint32_t length, bool is_notify)
 {
-  ASSERT(tud_configured(coreid), TUSB_ERROR_USBD_DEVICE_NOT_CONFIGURED);
+  ASSERT(tud_mounted(coreid), TUSB_ERROR_USBD_DEVICE_NOT_CONFIGURED);
 
   cdcd_data_t* p_cdc = &cdcd_data[coreid];
 
diff --git a/tinyusb/class/hid_device.c b/tinyusb/class/hid_device.c
index 5f8d9b53f..d06f71925 100644
--- a/tinyusb/class/hid_device.c
+++ b/tinyusb/class/hid_device.c
@@ -120,7 +120,7 @@ bool tud_hid_keyboard_busy(uint8_t coreid)
 
 tusb_error_t tud_hid_keyboard_send(uint8_t coreid, hid_keyboard_report_t const *p_report)
 {
-  ASSERT(tud_configured(coreid), TUSB_ERROR_USBD_DEVICE_NOT_CONFIGURED);
+  ASSERT(tud_mounted(coreid), TUSB_ERROR_USBD_DEVICE_NOT_CONFIGURED);
 
   hidd_interface_t * p_kbd = &keyboardd_data; // TODO &keyboardd_data[coreid];
 
@@ -143,7 +143,7 @@ bool tusbd_hid_mouse_is_busy(uint8_t coreid)
 
 tusb_error_t tusbd_hid_mouse_send(uint8_t coreid, hid_mouse_report_t const *p_report)
 {
-  ASSERT(tud_configured(coreid), TUSB_ERROR_USBD_DEVICE_NOT_CONFIGURED);
+  ASSERT(tud_mounted(coreid), TUSB_ERROR_USBD_DEVICE_NOT_CONFIGURED);
 
   hidd_interface_t * p_mouse = &moused_data; // TODO &keyboardd_data[coreid];
 
diff --git a/tinyusb/device/usbd.c b/tinyusb/device/usbd.c
index d10135151..0f7931f93 100644
--- a/tinyusb/device/usbd.c
+++ b/tinyusb/device/usbd.c
@@ -102,7 +102,7 @@ static tusb_error_t get_descriptor(uint8_t coreid, tusb_control_request_t const
 //--------------------------------------------------------------------+
 // APPLICATION INTERFACE
 //--------------------------------------------------------------------+
-bool tud_configured(uint8_t coreid)
+bool tud_mounted(uint8_t coreid)
 {
   return usbd_devices[coreid].state == TUSB_DEVICE_STATE_CONFIGURED;
 }
diff --git a/tinyusb/device/usbd.h b/tinyusb/device/usbd.h
index 55aad312a..59128db84 100644
--- a/tinyusb/device/usbd.h
+++ b/tinyusb/device/usbd.h
@@ -84,14 +84,15 @@ typedef struct {
   void (* const close) (uint8_t);
 } usbd_class_driver_t;
 
-//--------------------------------------------------------------------+
-// INTERNAL OBJECT & FUNCTION DECLARATION
-//--------------------------------------------------------------------+
-
 //--------------------------------------------------------------------+
 // APPLICATION API
 //--------------------------------------------------------------------+
-bool tud_configured(uint8_t coreid);
+bool tud_mounted(uint8_t coreid);
+
+/*------------- Callback -------------*/
+void tud_mount_cb(uint8_t coreid);
+void tud_umount_cb(uint8_t coreid);
+
 //void tud_device_suspended_cb(uint8_t coreid);
 
 //--------------------------------------------------------------------+