Define the following items as mailbox information:

1 ) Mailbox name: mbxid

2 ) Attribute (queuing method): mbxatr

3 ) System-reserved area: maxmpri

4 ) System-reserved area: mprihd

The number of mailbox information items that can be specified is defined as being within the range of 0 to 127.

The following shows the mailbox information format.

CRE_MBX ( mbxid, { mbxatr, maxmpri, mprihd } );

The items constituting the mailbox information are as follows.

1 ) Mailbox name: mbxid

Specifies the mailbox name.
An object name can be specified for mbxid.

Note The CF78V4 outputs to the system information header file the correspondence between the mailbox names and IDs, in the following format. Consequently, mailbox names can be used in the place of IDs by including the relevant system information header file using the processing program.

[ Output format to system information header file (for C) ]

#define mbxid ID

[ Output format to system information header file (for assembly language) ]

mbxid .EQU ID

2 ) Attribute (queuing method): mbxatr

Specifies the attributes (task queuing method, message queuing method) of the mailbox.
The keywords that can be specified for mbxatr are TA_TFIFO, TA_MFIFO and TA_MPRI.

[Task queuing method ]

TA_TFIFO: If the message could not be received from the mailbox (no messages were queued in the wait queue) when rcv_mbx or trcv_mbx is issued, the task is queued to the mailbox wait queue in the order of message reception request.

[ Message queuing method ]

TA_MFIFO: If a task is not queued to the mailbox wait queue when snd_mbx is issued, the message is queued to the mailbox wait queue in the order of message transmission request.

TA_MPRI: If a task is not queued to the mailbox wait queue when snd_mbx is issued, the message is queued to the mailbox wait queue in the order of message priority.

3 ) System-reserved area: maxmpri

System-reserved area.
Values that can be specified for maxmpri are limited to 0.

4 ) System-reserved area: mprihd

System-reserved area.
The keywords that can be specified for mprihd are NULL.