Use a target timer to signal a semaphore when a target time is reached.

HPESTATUS hpeSetTargetTimer(
    HPEHANDLE devhandle, 
    DWORD idx, 
    HPE_1588_TIMESTAMP *time, 
    QWORD ns_delta, 
    KNHANDLE sem
);

Parameters

devhandle

A handle value for the device.

idx

Timer instance, 0 or 1.

time

The time at which to signal the semaphore. This may be a system time obtained via hep1588GetSystemTime with some delta added with hpe1588TimeAdd. May be NULL if sem is NULL, in which case the timer is canceled.

ns_delta

The delta time at which to signal the semaphore.

sem

A KNHANDLE for the (low-level) semaphore to signal. A NULL value cancels the timer.

Remarks

Small values of us_delta (< 50us) may result in heavy CPU load (depending on the CPU and other system factors). If “time” is less than the actual system time, the semaphore is never signaled. Canceling a timer may leave outstanding units on a semaphore if they have not been consumed by the application. If the system time is adjusted (by way of hpe1588SetSystemTime, hpe1588AdjustSystemTime) timers may be extended or missed. If a periodic timer is required it may be advantageous to use a “one shot” timer (us_delta = 0). This will allow the application to compensate for propagation delay incurred when configuring the timer.

Return Values

A status value indicating the success or failure of the operation:

Requirements