OS_DynTickGet

Description

OS_DynTickGet() is part of the dynamic tick mechanism and must be implemented in the BSP. During dynamic tick operation, the kernel specifies the number of ticks, Delta1, that must expire before an interrupt is fired. When Delta1 is specified, OS_DynTickGet() acts as an up-counter from 0 to Delta1, with each count representing a single tick of elapsed time. Once the count reaches Delta1, OS_DynTickGet() must return Delta1 until a new Delta is set by the kernel. Returning a value greater than Delta1 will impact the system timing in unexpected ways, so it is critical that this restriction be followed.

Files

os.h/bsp_os.c

Prototype

OS_TICK  OS_DynTickGet (void)

Arguments

None.

Returned Value

The number of ticks which have elapsed since the kernel last set a dynamic tick timeout.

Required Configuration

OS_CFG_TICK_EN and OS_CFG_DYN_TICK_EN must be enabled in os_cfg.h.

Notes/Warnings

1. To use the Dynamic Tick feature, the OS Board Support Package (BSP) should implement the Dynamic Tick API defined in Dynamic Tick BSP.
2. Do not call OS_DynTickGet() from your application.
3. OS_DynTickGet() is always called within a critical section.
4. If your port supports Non-Kernel Aware interrupts, make sure that the dynamic tick interrupt is assigned a kernel-aware priority.