USBB17RX78K4-XXX NEC Electronics, USBB17RX78K4-XXX Datasheet - Page 33

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

3.1.2 Configuration of ready queue and dispatching
READY state. At this time, RX78K/IV references a ready queue.
a ready queue has the highest priority of the tasks in the queue, and the task chained to the tail of the queue has the
lowest priority. Among these priority levels, levels 2 to 15 can be specified for a task.
state. However, if there is no executable user task at that time, it sets the CPU in the HALT mode. To resume
execution of a user task, therefore, an interrupt must be used. The stack area at that time becomes the user stack
area.
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When RX78K/IV passes CPU execution privilege to a task, it searches for a task having the highest priority in the
RX78K/IV has 16 ready queues each corresponding to 16 priority levels (0 to 15). The task chained to the head of
RX78K/IV searches the ready queues from the one having the highest priority for a task to be placed in the RUN
Fig. 3-3 shows the configuration of the ready queue.
Ready queue
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CHAPTER 3
RX78K/IV BASIC OPERATIONS AND CONTROL BLOCKS
Fig. 3-3 Ready Queue Configuration
Queue area
Information
particular
to the task
TCB1
Queue area
Information
particular
to the task
TCB2
Queue area
Information
particular
to the task
TCBn