3.4.2.2 Library Overview
The USB CDC Host Client Driver API is grouped functionally, as shown in the following table.
| Library Interface Section | Description |
| Client Access Functions | These functions allow application clients to open, close the client
and register event handlers. These functions are implemented in
usb_host_cdc.c. |
| Data Transfer Functions | These functions allow the application client to transfer data to the
attached device. These functions are implemented in
usb_host_cdc.c. |
| CDC Class-specific Command Functions | These functions allow the application to send class specific control
transfer requests to the application. These functions are implemented in
usb_host_cdc_acm.c. |