SWRU271I October 2010 – January 2020 CC2540 , CC2540T , CC2541 , CC2541-Q1 , CC2640R2F
The HCI layer is a thin layer that transports commands and events between the host and controller. In a network processor application, the HCI layer is implemented by a transport protocol such as SPI or UART. In embedded SoC projects, the HCI layer is implemented through function calls and callbacks. The commands and events discussed previously in this guide pass from the given layer through the HCI layer to the controller and through the controller to the HCI layer.