SWRU271I October 2010 – January 2020 CC2540 , CC2540T , CC2541 , CC2541-Q1 , CC2640R2F
The Bluetooth Low Energy protocol stack, profiles, and applications are built around the OSAL. The OSAL is a control loop that lets software set up how events should execute. Each layer of software functions as a task and requires a task identifier (ID), a task initialization routine, and an event processing routine. You can also define a message processing routine. These layers must adhere to a priority scheme with the LL as the highest priority because of its timing requirements. The following is the hierarchy from the SimpleBLEPeripheral project:
The OSAL also provides services such as message passing, heap management, and timers. OSAL code is provided in source form. For more information on the OSAL functions, see the OSAL API Guide.