diff options
Diffstat (limited to 'doc/user/clock.t')
| -rw-r--r-- | doc/user/clock.t | 31 |
1 files changed, 10 insertions, 21 deletions
diff --git a/doc/user/clock.t b/doc/user/clock.t index fdbd91db21..921d1cbbe8 100644 --- a/doc/user/clock.t +++ b/doc/user/clock.t @@ -20,7 +20,7 @@ the clock manager are: @item @code{@value{DIRPREFIX}clock_get_tod_timeval} - Get date and time in timeval format @item @code{@value{DIRPREFIX}clock_get_seconds_since_epoch} - Get seconds since epoch @item @code{@value{DIRPREFIX}clock_get_ticks_per_second} - Get ticks per second -@item @code{@value{DIRPREFIX}clock_get_ticks_since_boot} - Get ticks since boot +@item @code{@value{DIRPREFIX}clock_get_ticks_since_boot} - Get current ticks counter value @item @code{@value{DIRPREFIX}clock_get_uptime} - Get time since boot @item @code{@value{DIRPREFIX}clock_get_uptime_timeval} - Get time since boot in timeval format @item @code{@value{DIRPREFIX}clock_get_uptime_seconds} - Get seconds since boot @@ -569,19 +569,16 @@ application has configured. 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 -@code{@value{DIRPREFIX}clock_set} is required to re-initialize the -system date and time to application specific specifications. +This directive will not cause the running task to be preempted. @c @c @c @page -@subsection CLOCK_GET_TICKS_SINCE_BOOT - Get ticks since boot +@subsection CLOCK_GET_TICKS_SINCE_BOOT - Get current ticks counter value @cindex obtain ticks since boot +@cindex get current ticks counter value @subheading CALLING SEQUENCE: @@ -604,25 +601,17 @@ NONE @subheading DESCRIPTION: -This directive returns the number of clock ticks that have elapsed -since the system was booted. This is the historical measure of uptime -in an RTEMS system. The newer service -@code{@value{DIRPREFIX}clock_get_uptime} is another and potentially -more accurate way of obtaining similar information. +This directive returns the current tick counter value. With a 1ms clock tick, +this counter overflows after 50 days since boot. This is the historical +measure of uptime in an RTEMS system. The newer service +@code{@value{DIRPREFIX}clock_get_uptime} is another and potentially more +accurate way of obtaining similar information. @subheading NOTES: 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 -@code{@value{DIRPREFIX}clock_set} is required to re-initialize the -system date and time to application specific specifications. - -This directive simply returns the number of times the dirivective -@code{@value{DIRPREFIX}clock_tick} has been invoked since the -system was booted. +This directive will not cause the running task to be preempted. @c @c |