/*
*********************************************************************************************************
* PROCESS SYSTEM TICK
*
* Description: This function is used to signal to uC/OS-II the occurrence of a 'system tick' (also known
* as a 'clock tick'). This function should be called by the ticker ISR but, can also be
* called by a high priority task.
*
* Arguments : none
*
* Returns : none
*********************************************************************************************************
*/
void OSTimeTick (void)
This is from os_core.c. uOS might work "without" a timer but then of course the timebase becomes "shaky" at best.
The mentioned "high priority task" might also consume a lot of CPU to busy waits.
I would recommend to use a real HW timer.
karsten