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Altera_Forum
Honored Contributor
Honored ContributorPeriodL & PeriodH
I understand that timeout period determines the period of your interrupt.
I also understand that periodL and periodH is holds the LSB and MSB 16bit value of the period register. My question is how do i know what value to put into these registers to change my timeout period?3 Replies
Altera_Forumperiod register = timeout period x timer frequency
For example if your timer runs at 50Mhz and you need a 50ms period, you must write the period register 0.05 x 50M = 2500000. 2500000 dec = 2625a0 hex : then periodH = 0x26 and periodL = 0x25a0.- Altera_Forum
It seems strange to me that Altera haven't supplied 32bit versions of the timer devices. I presume the 16bit versions have been carried forwards from an earlier design - It isn't as though a 32bit version would be difficult to write from scratch!
It is worth checking that you don't need to subtract 1 from the count - check the datasheet/pdf. - Altera_Forum
Sorry, actually the correct formula is:
period register = timeout period x timer frequency - 1 Thanks to dsl for pointing out the mistake.
