IPC@CHIP Documentation - SC12 @CHIP-RTOS V1.10

period should still be keep to some reasonable small amount of time. Note that task locks also inhibit
all system timer activity.
Critical Section Protection Methods Summary
The design trade-offs for the three methods presented above for protecting critical sections are
summarized in Table 3.
Method Advantage Limitations
Semaphore A long duration of critical section
does not adversely affect portions of
system not accessing the
semaphore.
Interrupt Mask Most efficient of all three methods.
(Executes quickly!)
No priority inversion
Can result in a priority inversion.
Impact on system operation becomes
a concern if interrupt mask time can
exceed around 50 us.
Task Lock No priority inversion. Impact on system operation becomes
questionable if task lock duration
exceeds around 400 us.
Table 3 ) Critical Section Protection Methods
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Control and Communication between Tasks
The @Chip-RTOS provides the following mechanisms for tasks to control one another and to communicate.
These interactions can either be between tasks within the same DOS application, or across applications.
● Semaphores
● Event Groups
● Message Exchanges
The usage of these @Chip-RTOS resources is covered in depth within the on-line HTML help.
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