USBB17RX78K4-XXX NEC Electronics, USBB17RX78K4-XXX Datasheet - Page 21

• Manufacturer Part Number: USBB17RX78K4-XXX
• Description: 78K/4 series realtime OS
• Manufacturer: NEC Electronics

2.3 Synchronization and Communication
tasks in parallel and thereby to organize one system, it is necessary to control execution flow of the tasks, manage
the resources shared by the tasks, and transfer information among tasks. Synchronization and communication are to
implement these functions.
other task has completed its work. In this case, the two tasks have a cooperative relationship. The mutual exclusion
mode is used, when two tasks are using a common resource, to prevent one task from using the resource while the
other task is using it. In this case, the two tasks are in a competitive relationship.
cannot proceed with processing until it has received the message. Therefore, the communication function can also
be used in the place of the synchronization function.
for synchronization, and mail boxes for communication.
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A task is executed under its own environments as an independent program. To execute two or more independent
Synchronization is performed in two modes: wait and mutual exclusion.
The wait mode is used, when two tasks play the respective roles of work, to stop the work of one task until the
Communication between tasks is for transferring a message between tasks. A task that is to receive the message
As a means to implement synchronization and communication, RX78K/IV provides event flags and semaphores
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV