USBB17RX78K4-XXX NEC Electronics, USBB17RX78K4-XXX Datasheet - Page 24

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

2.3.3 Mail box
queue of messages waiting to be transmitted.
message has not arrived after “rcv_msg” has been issued, the task enters the WAIT state and queued to the mail
box. If the task has issued “prcv_msg”, it does not enter the WAIT state, but an error code is returned. A task can
also send a message to a mail box by issuing system call “snd_msg”. If there is a task waiting for the message, that
task is released from the WAIT state and the message is transmitted to that task. If there is no waiting task, the
message is queued. Messages and tasks are queued on a FIF0 basis only.
A mail box transmits messages between tasks and has a queue of tasks waiting for reception of a message and a
A task can request reception of a message from a mail box by issuing system call “rcv_msg” or “prcv_msg”. If the
CHAPTER 2
BASIC FUNCTIONS OF RX78K/IV
15