13.4.4 Data queue information

Define the following items as data qutue information:

1 ) ID number: dtqid

2 ) Attribute: dtqatr

3 ) Data count: dtqcnt, memory area name: sec_nam

4 ) Reserved for future use: dtq

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

The following shows the data queue information format.

 CRE_DTQ (dtqid, { dtqatr, dtqcnt[:sec_nam], dtq });


The items constituting the data queue information are as follows.

1 ) ID number: dtqid

Specifies the ID number for a data queue.
A value from 0x1 to 0xff, or a name, can be specified for dtqid.


Note When a name is specified, the CF78V4 automatically assigns an ID number.
The CF78V4 outputs the relationship between a name and an ID number to the system information header file in the following format:


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

 #define dtqid   ID


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

 dtqid   .EQU     ID


2 ) Attribute: dtqatr

Specifies the task queuing method for a data queue.
The keyword that can be specified for dtqatr is TA_TFIFO only.


TA_TFIFO: Task wait queue is in FIFO order.

3 ) Data count: dtqcnt, memory area name: sec_nam

Specifies the maximum number of data units that can be queued to the data queue area of a data queue, and the name of the memory area secured for the data queue area.
Only values from 0x0 to 0xff can be specified for dtqcnt, and only memory area name "kernel_work0, kernel_work1, kernel_work2, kernel_work3" can be specified for sec_nam.




[ section for data allocation ]

kernel_work0 allocates data queue to .kernel_work0 section

kernel_work1 allocates data queue to .kernel_work1 section

kernel_work2 allocates data queue to .kernel_work2 section

kernel_work3 allocates data queue to .kernel_work3 section

4 ) Reserved for future use: dtq

System-reserved area.
Values that can be specified for dtq are limited to NULL characters.