procedure Clock_Get ( Option : in RTEMS.Clock_Get_Options; Time_Buffer : in RTEMS.Address; Result : out RTEMS.Status_Codes );
RTEMS.SUCCESSFUL
- current time obtained successfully
RTEMS.NOT_DEFINED
- system date and time is not set
This directive obtains the system date and time. If
the caller is attempting to obtain the date and time (i.e.
option is set to either RTEMS.CLOCK_GET_SECONDS_SINCE_EPOCH
,
RTEMS.CLOCK_GET_TOD
, or
RTEMS.CLOCK_GET_TIME_VALUE
) and the date and time
has not been set with a previous call to
rtems.clock_set
, then the
RTEMS.NOT_DEFINED
status code is returned.
The caller can always obtain the number of ticks per second (option is
RTEMS.CLOCK_GET_TICKS_PER_SECOND
) and the number of
ticks since the executive was initialized option is
RTEMS.CLOCK_GET_TICKS_SINCE_BOOT
).
The option
argument may taken on any value of the enumerated
type rtems_clock_get_options
. The data type expected for
time_buffer
is based on the value of option
as
indicated below:
RTEMS.CLOCK_GET_TOD
- Address of an variable of
type RTEMS.Time_Of_Day
RTEMS.CLOCK_GET_TIME_VALUE
- Address of an variable of
type RTEMS.Clock_Time_Value
RTEMS.CLOCK_GET_TICKS_SINCE_BOOT
- Address of an
variable of type RTEMS.Interval
RTEMS.CLOCK_GET_SECONDS_SINCE_EPOCH
- Address of an
variable of type RTEMS.Interval
RTEMS.CLOCK_GET_TICKS_PER_SECOND
- Address of an
variable of type RTEMS.Interval
This directive is callable from an ISR.
This directive will not cause the running task to be
preempted. Re-initializing RTEMS causes the system date and
time to be reset to an uninitialized state. Another call to
rtems.clock_set
is required to re-initialize the
system date and time to application specific specifications.
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