RTEMS 4.8.1 On-Line Library

Clock Manager CLOCK_SET_NANOSECONDS_EXTENSION - Install the nanoseconds since last tick handler

RTEMS C User's Guide

7.4.3: CLOCK_SET_NANOSECONDS_EXTENSION - Install the nanoseconds since last tick handler

CALLING SEQUENCE:

rtems_status_code rtems_clock_set_nanoseconds_extension(
  rtems_nanoseconds_extension_routine routine
);

DIRECTIVE STATUS CODES:

RTEMS_SUCCESSFUL - clock tick processed successfully
RTEMS_INVALID_ADDRESS - time_buffer is NULL

DESCRIPTION:

This directive is used by the Clock device driver to install the routine which will be invoked by the internal RTEMS method used to obtain a highly accurate time of day. It is usually called during the initialization of the driver.

When the routine is invoked, it will determine the number of nanoseconds which have elapsed since the last invocation of the rtems_clock_tick directive. It should do this as quickly as possible with as little impact as possible on the device used as a clock source.

NOTES:

This directive may be called from an ISR.

This directive is called as part of every service to obtain the current date and time as well as timestamps.

RTEMS C User's Guide