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If the call was successful and the desired task was suspended.
OS_ERR_INT_Q_FULL
If OS_CFG_ISR_POST_DEFERRED_EN is to DEF_ENABLED in os_cfg.h: If the deferred interrupt post queue is full.
OS_ERR_OS_NOT_RUNNING
If OS_CFG_INVALID_OS_CALLS_CHK_EN is set to DEF_ENABLED in os_cfg.h: if µC/OS-III is not running yet.
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