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CHAPTER 13 SERVICE CALLS
User’s Manual U14833EJ2V0UM
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The task creation packet T_CTSK is described in detail below.
tskatr
Specifies data such as whether the coprocessor is used or not and whether interrupts are enabled or disabled at
activation as task attributes. Values that can be specified as task attributes are shown below.
Figure 13-2. Task Attributes
tskatr
15
8
7
0
TA_ASM (1): Described in assembly language
TA_HLNG (0): Described in C language
TA_COP (1): Use coprocessor
TA_DISINT (1): Activate task in interrupt disabled state
TA_ENAINT (0): Activate task in interrupt enabled state
TA_ACT (1): Activate immediately after the task creation
Bit 0 is used to specify the task’s description language. TA_HLNG is specified if the task is described in C
language and TA_ASM if assembly language is used. In this version, however, there are no differences in the
processing for these two attributes.
Bit 1 is used to specify whether a task is to be activated after creation. If the attribute TA_STA is assigned to a
task, act_tsk or equivalent processing is performed for that task after it is created.
Bit 12 is used to specify whether interrupts are enabled or disabled immediately after a created task is activated.
If TA_DISINT is set, the task is activated in the interrupt disabled state. If TA_ENAINT is set, the task is activated
in the interrupt enabled state. Note that disabling interrupts means that interrupts that can initiate interrupt
processing in which kernel services are received are masked.
Bit 14 is used to specify whether the created task will use the coprocessor (FPU). If TA_COP is set, the
preprocessing and postprocessing required when the coprocessor is used is performed.
Note that when a combination of these attributes is set, the logical sum of the above values is set for tskatr.
exinf
Stores user-specific information regarding the creation of tasks. This information can be referenced as
parameters for tasks activated by (i)act_tsk.
task
Sets the activation address of the task to be created.
itskpri
Sets the initial priority (task initial priority) of the task to be created. When a task that has been terminated is
reactivated, the priority of that task is determined by the value set in itskpri and not by the value at termination.
The range of the values that can be specified for itskpri is from 0x1 to the maximum priority (specified by the CF
definition file).