OSTaskRegSet()

Unable to render {include} The included page could not be found.

OSTaskRegSet()

void OSTaskRegSet (OS_TCB *p_tcb,

OS_REG_ID id,

OS_REG value,

OS_ERR *p_err)

File	Called from	Code enabled by
os_task.c	Task only	OS_CFG_TASK_REG_TBL_SIZE > 0

µC/OS-III allows the user to store task-specific values in task registers. Task registers are different than CPU registers and are used to save such information as “errno,” which are common in software components. Task registers can also store task-related data to be associated with the task at run time such as I/O register settings, configuration values, etc. A task may have as many as OS_CFG_TASK_REG_TBL_SIZE registers, and all registers have a data type of OS_REG. However, OS_REG can be declared at compile time to be nearly anything (8-, 16-, 32-, 64-bit signed or unsigned integer, or floating-point).

As shown below, a task register is changed by calling OSTaskRegSet(), and read by calling OSTaskRegGet(). The desired task register is specified as an argument to these functions and can take a value between 0 and OS_CFG_TASK_REG_TBL_SIZE-1.

Arguments

p_tcb

is a pointer to the TCB of the task you are setting. A NULL pointer indicates that the user wants to set the value of a task register of the calling task.

id

is the identifier of the task register and valid values are from 0 to OS_CFG_TASK_REG_TBL_SIZE-1.

value

is the new value of the task register specified by id.

p_err

is a pointer to a variable that will contain an error code returned by this function.

OS_ERR_NONE

if the call was successful, and the function set the value of the desired task register.

OS_ERR_REG_ID_INVALID

if OS_CFG_ARG_CHK_EN is set to 1 in os_cfg.h: if a valid task register identifier is not specified.

Returned Value

None

Notes/Warnings

None

Example

OS_TCB MyTaskTCB;

void TaskX (void *p_arg)

{

OS_ERR err;

while (DEF_ON) {

:

reg = OSTaskRegSet(&MyTaskTCB,

5,

23,

&err);

/* Check “err” */

:

}