Re: CPU AND peripheral clocks
- From: Jim Granville <no.spam@xxxxxxxxxxxxxxxxxxxxxx>
- Date: Fri, 29 Feb 2008 12:52:22 +1300
vivek wrote:
Why are peripheral clocks divided by 2 or 4 or by 8 times of the CPU
clock?
Why can't they run at CPU core clock speed?
This is just a general question and not restricted to any processor or
architecture.
They can - Which chip(s) are you talking about ?
In some chips, the peripherals can clock faster : USB and Special PWM
timers are examples.
It would be nice to clock ANY Peripherals FASTER than the core in
some cases, but life gets tricky here : Those peripherals
need to interact with the SFR flags, and it is not trivial to allow
fast HW and (now slower) core, share the same SFR flags.
So most uC that have clock prescalers, change the clock to the Core
and peripherals at the same time, because that's avoids any special flag handling.
-jg
.
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