diff --git a/src/class/cdc/cdc_host.c b/src/class/cdc/cdc_host.c
index 6eadca23..2968fb57 100644
--- a/src/class/cdc/cdc_host.c
+++ b/src/class/cdc/cdc_host.c
@@ -55,16 +55,16 @@
 //--------------------------------------------------------------------+
 // INTERNAL OBJECT & FUNCTION DECLARATION
 //--------------------------------------------------------------------+
-STATIC_VAR cdch_data_t cdch_data[CFG_TUSB_HOST_DEVICE_MAX]; // TODO to be static
+static cdch_data_t cdch_data[CFG_TUSB_HOST_DEVICE_MAX]; // TODO to be static
 
-static inline bool tusbh_cdc_is_mounted(uint8_t dev_addr)
+static inline bool tuh_cdc_mounted(uint8_t dev_addr)
 {
   return pipehandle_is_valid(cdch_data[dev_addr-1].pipe_in) && pipehandle_is_valid(cdch_data[dev_addr-1].pipe_out);
 }
 
 bool tuh_cdc_is_busy(uint8_t dev_addr, cdc_pipeid_t pipeid)
 {
-  if ( !tusbh_cdc_is_mounted(dev_addr) ) return false;
+  if ( !tuh_cdc_mounted(dev_addr) ) return false;
 
   cdch_data_t const * p_cdc = &cdch_data[dev_addr-1];
 
@@ -90,14 +90,14 @@ bool tuh_cdc_is_busy(uint8_t dev_addr, cdc_pipeid_t pipeid)
 bool tuh_cdc_serial_is_mounted(uint8_t dev_addr)
 {
   // TODO consider all AT Command as serial candidate
-  return tusbh_cdc_is_mounted(dev_addr)                                         &&
+  return tuh_cdc_mounted(dev_addr)                                         &&
       (CDC_COMM_PROTOCOL_ATCOMMAND <= cdch_data[dev_addr-1].interface_protocol) &&
       (cdch_data[dev_addr-1].interface_protocol <= CDC_COMM_PROTOCOL_ATCOMMAND_CDMA);
 }
 
 tusb_error_t tuh_cdc_send(uint8_t dev_addr, void const * p_data, uint32_t length, bool is_notify)
 {
-  TU_ASSERT( tusbh_cdc_is_mounted(dev_addr),  TUSB_ERROR_CDCH_DEVICE_NOT_MOUNTED);
+  TU_ASSERT( tuh_cdc_mounted(dev_addr),  TUSB_ERROR_CDCH_DEVICE_NOT_MOUNTED);
   TU_ASSERT( p_data != NULL && length, TUSB_ERROR_INVALID_PARA);
 
   pipe_handle_t pipe_out = cdch_data[dev_addr-1].pipe_out;
@@ -108,7 +108,7 @@ tusb_error_t tuh_cdc_send(uint8_t dev_addr, void const * p_data, uint32_t length
 
 tusb_error_t tuh_cdc_receive(uint8_t dev_addr, void * p_buffer, uint32_t length, bool is_notify)
 {
-  TU_ASSERT( tusbh_cdc_is_mounted(dev_addr),  TUSB_ERROR_CDCH_DEVICE_NOT_MOUNTED);
+  TU_ASSERT( tuh_cdc_mounted(dev_addr),  TUSB_ERROR_CDCH_DEVICE_NOT_MOUNTED);
   TU_ASSERT( p_buffer != NULL && length, TUSB_ERROR_INVALID_PARA);
 
   pipe_handle_t pipe_in = cdch_data[dev_addr-1].pipe_in;
@@ -212,7 +212,7 @@ bool cdch_open_subtask(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t c
   return true;
 }
 
-void cdch_isr(uint8_t dev_addr, xfer_result_t event, uint32_t xferred_bytes)
+void cdch_isr(uint8_t dev_addr, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes)
 {
   tuh_cdc_xfer_isr( dev_addr, event, 0, xferred_bytes );
 }
diff --git a/src/class/cdc/cdc_host.h b/src/class/cdc/cdc_host.h
index 02eaa16e..2fbd40f4 100644
--- a/src/class/cdc/cdc_host.h
+++ b/src/class/cdc/cdc_host.h
@@ -147,11 +147,9 @@ typedef struct {
 
 } cdch_data_t;
 
-extern cdch_data_t cdch_data[CFG_TUSB_HOST_DEVICE_MAX]; // TODO consider to move to cdch internal header file
-
 void cdch_init(void);
 bool cdch_open_subtask(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *p_interface_desc, uint16_t *p_length) ATTR_WARN_UNUSED_RESULT;
-void cdch_isr(uint8_t dev_addr, xfer_result_t event, uint32_t xferred_bytes);
+void cdch_isr(uint8_t dev_addr, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes);
 void cdch_close(uint8_t dev_addr);
 
 #endif
diff --git a/src/host/usbh.c b/src/host/usbh.c
index ff9ca966..c345ddf0 100644
--- a/src/host/usbh.c
+++ b/src/host/usbh.c
@@ -273,7 +273,7 @@ void hcd_event_xfer_complete(uint8_t dev_addr, uint8_t ep_addr, xfer_result_t ev
 
     if (usbh_class_drivers[drv_id].isr)
     {
-      usbh_class_drivers[drv_id].isr(dev_addr , event, xferred_bytes);
+      usbh_class_drivers[drv_id].isr(dev_addr, ep_addr, event, xferred_bytes);
     }
     else
     {
diff --git a/src/host/usbh.h b/src/host/usbh.h
index de43c8a4..390b0405 100644
--- a/src/host/usbh.h
+++ b/src/host/usbh.h
@@ -67,8 +67,8 @@ typedef struct {
   uint8_t class_code;
 
   void (* const init) (void);
-  bool (* const open_subtask)(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *, uint16_t* outlen);
-  void (* const isr) (uint8_t dev_addr, xfer_result_t, uint32_t);
+  bool (* const open_subtask)(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const * itf_desc, uint16_t* outlen);
+  void (* const isr) (uint8_t dev_addr, uint8_t ep_addr, xfer_result_t result, uint32_t len);
   void (* const close) (uint8_t);
 } host_class_driver_t;
 //--------------------------------------------------------------------+