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Altera_Forum
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20 years ago

altera timer hal overflow question ?

do altera hal timers work correct if the end of the system tick variable range is reached ? Please check the following and tell me if I'm wrong. see files alt_tick.c, alt_alarm_st...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
20 years ago

Hi Fischer,

Which Nios II version are you looking at? I currently have Nios II 5.1, and in Nios II 5.1 there is a roll-over flag -for each alarm- that handles the wraparound of the timer.

Although it has not the wraparound problem, as a general comment, the alarm implementation used by the HAL could be optimized: now it has an overall O(t*n) complexity, where t is the mean number of ticks of each alarm, and n is the number of alarms... If the alarm ticks are stored in an incremental way (like we do in the OSEK alarms implemented in ERIKA Enterprise), you can save some time when the numbre of alarms grows up...

bye

Paolo