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SWRU271H – October 2010 – Revised April 2019
Copyright © 2010–2019, Texas Instruments Incorporated
The Operating System Abstraction Layer (OSAL)
Chapter 3
SWRU271H – October 2010 – Revised April 2019
The Operating System Abstraction Layer (OSAL)
3.1
Overview
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