Renesas 70 - Manual (Page 34)

Chapter 3 Introduction to MR308
- 24 -
3.3.3 Task Priority and Waiting Queue
In The standard profiles in µITRON 4.0 Specification support two waiting methods for each object. In one
method, tasks are placed in a waiting queue in order of priority (TA_TPRI attribute); in another, tasks are placed
in a waiting queue in order of FIFO (TA_TFIFO).
Figure 3.15 and Figure 3.16 depict the manner in which tasks are placed in a waiting queue in order of
"taskD," "taskC," "taskA," and "taskB."
n
Priority 1 Priority 5 Priority 6
taskB
1
ID No.
2 taskA taskC taskD
Priority 9
Figure 3.15 Waiting queue of the TA_TPRI attribute
n
Priority 9 Priority 6 Priority 1
taskC
1
ID No.
2 taskD taskA taskB
Priority 5
Figure 3.16 Waiting queue of the TA_TFIFO attribute