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There are a number of operations the application is able to perform on semaphores, summarized in the table below. In this chapter, only the three most used functions used most often are discussed: OSSemCreate(), OSSemPend(), and OSSemPost(). Other The other functions are described in ?C µC/OS-III API Reference. When semaphores are used for sharing resources, every semaphore function must be called from a task and never from an ISR. The same limitation does not apply when using semaphores for signaling.
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