Comtrol eCos - Manual (Page 60)

Counters
off between doing work whenever a new alarm is added to a counter and doing work whenever a tick occurs. It is
application-dependent which of these is more appropriate.
Valid contexts
cyg_counter_create is typically called during system initialization but may also be called in thread
context. Similarly cyg_counter_delete may be called during initialization or in thread context.
cyg_counter_current_value , cyg_counter_set_value and cyg_counter_tick may be called during
initialization or from thread or DSR context. In fact, cyg_counter_tick is usually called from inside a DSR in
response to an external event of some sort.
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