I have an ARM 9 (STR91x micro) program using os_dly_wait(1) for a 1 tick delay (10ms). However,the delay is about 3ms. I know that on some RTOS a delay of 1 tick delays for the remainder of the tick so it could be a delay of anything between 1 and 10ms. This appears to be what Keil (v4.74) is doing. However, the keil documentation and examples do not show this and imply that a timer is started (usually timer 0) and a delay of 1 = 1 whole tick. Perhaps this is true for Cortex but not ARM 9 variants of RL-ARM? Anyone know more about this? Thanks.
It appears that a delay of 1 tick does not guarantee a complete tick, as I observed and as explained at http://www.keil.com/support/docs/3766.htm. It would have been useful if this was documented in the function documentation rather than as a separate support document.