Chapter 3 Introduction to MR308
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3.3.4 Task Control Block(TCB)
The task control block (TCB) refers to the data block that the real-time OS uses for individual task status, priority,
and other control purposes.
The MR308 manages the following task information as the task control block
• Task connection pointer
Task connection pointer used for ready queue formation or other purposes.
• Task status
• Task priority
• Task register information and other data26 storage stack area pointer(current SP register value)
• Wake-up counter
Task wake-up request storage area.
• Time-out counter or wait flag pattern
When a task is in a time-out wait state, the remaining wait time is stored; if in a flag wait state, the
flag's wait pattern is stored in this area.
• Flag wait mode
This is a wait mode during eventflag wait.
• Timer queue connection pointer
This area is used when using the timeout function. This area stores the task connection pointer used
when constructing the timer queue.
• Flag wait pattern
This area is used when using the timeout function.
This area stores the flag wait pattern when using the eventflag wait service call with the timeout func-
tion (twai_flg). No flag wait pattern area is allocated when the eventflag is not used.
• Startup request counter
This is the area in which task startup requests are accumulated.
• Extended task information
Extended task information that was set during task generation is stored in this area.
The task control block is schematized in Figure 3.17.
26 Called the task context