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RE: Re: How to set clock related options?
- From: Savin Zlobec <savin at elatec dot si>
- To: caocangmou at sina dot com
- Cc: ecos-discuss at sources dot redhat dot com
- Date: Thu, 25 Sep 2003 15:10:08 +0200
- Subject: [ECOS] RE: Re: How to set clock related options?
caocangmou wrote:
But, I got a configuration from template(Akizuki H8/3068) :
Real-time clock numerator : 1000000000
Real-time clock denominator : 100
Real-time clock base prescale : 8192
Real-time clock period :10
OSC/Clock Frequency :20000000
It seems not the case .What does period really mean?
CYGNUM_KERNEL_COUNTERS_RTC_PERIOD which defaults to
CYGNUM_HAL_RTC_PERIOD is
used to initialize you system clock hardware. Ecos tick is usually
implemented with a hw timer which gives
periodic interrupts. The CYGNUM_HAL_RTC_PERIOD is calculated so that
you get an interrupt every
10ms (the default) and it depends on your timer hardware. Changing the
tick requires setting the
CYGNUM_HAL_RTC_NUMERATOR, CYGNUM_HAL_RTC_DENOMINATOR and
CYGNUM_HAL_RTC_PERIOD (if it is not automatically calculated from the
previous two - look how it is
calculated in cdl - it can only depend on your frequency - in that case
it is probably set to 10ms).
savin
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