USBB17RX78K4-XXX NEC Electronics, USBB17RX78K4-XXX Datasheet - Page 22

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

2.3.1 Event flag
other flags.
event does not occur, the issuing task enters the WAIT state (when wai_flg or cwai_flg is issued). If the task does
not enter the WAIT state, an error code is returned (when pol_flg or cpol_flg is issued).
tasks.
tasks placed in the WAIT state specifies clearing the flag (cwai_flg), the event flag is cleared after that task has been
released from the WAIT state. Therefore, the tasks following that task are not released from the WAIT state.
An event flag is used to make a task wait. Since an event flag is a 1-bit flag, it is not ORed or ANDed with the
A task issues system call “wai_flg”, “cwai_flg” or “pol_flg”, “cpol_flg” to wait for an occurrence of an event. If the
To inform the occurrence of the event, system call “set_flg” is issued.
The event flag is cleared by system call “clr_flg”.
An event flag can be used to place two or more tasks in the WAIT state. Therefore, the event flag can queue
In this case, the tasks are released from the WAIT state when “set_flg” is issued once. If at least one task of the
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
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