Zhengsu Gao wrote: > Thank you, chris. > > You know I am now working on one problem. I need 8MHz to run some > low- requency-burst heavy load task, and generally the system runs one > light weight task( I want it to run in 1 MHz to save some energy). Can > you give me some suggestions about this case?
if you don't need an accurate clock in the "fast" phase, you could use DCOCLK at it max values for MCLK. this means that the CPU runs at about 5MHz. this frequency won't be temperature stable and is somewhat lower than your 8MHz. you may be able to use a watch crystal (32768Hz) at XT1. it can be used for the Timer_A (and maybe Watchdog) module. this way you'd have a accurate time and still a fast CPU. chris > Thank you! > > Regards > Zhengsu Gao > > However, if I use on 8 MHz crystal, while di > ----- Original Message ----- From: "Chris Liechti" <[email protected]> > To: <[email protected]> > Sent: Friday, December 03, 2004 5:05 PM > Subject: Re: [Mspgcc-users] About system fequency > > >> Gao Zhengsu wrote: >> >>> Hi, everybody: >>> I have a question about system frequency. When I use an 8 MHz crystal in >>> XT2, can I change system frequency from 8MHz to 1MHz simply by >>> divider at run >>> time without losing anything. >> >> >> basicaly yes, div 8 is the highest divider you can select in the basic >> clock module and you can switch it at runtime. >> switching clocks can be tricky in some cases, e.g. if you want to have a >> realtime clock running accurately. >> >> it's not the same as connecting a lower frequency crystal. in general >> faster clocks use more current. so using a faster crystal than you need >> means less battery life. >> >> chris >> >> >> ------------------------------------------------------- >> SF email is sponsored by - The IT Product Guide >> Read honest & candid reviews on hundreds of IT Products from real users. >> Discover which products truly live up to the hype. Start reading now. >> http://productguide.itmanagersjournal.com/ >> _______________________________________________ >> Mspgcc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/mspgcc-users >> > > > > > ------------------------------------------------------- > SF email is sponsored by - The IT Product Guide > Read honest & candid reviews on hundreds of IT Products from real users. > Discover which products truly live up to the hype. Start reading now. > http://productguide.itmanagersjournal.com/ > _______________________________________________ > Mspgcc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/mspgcc-users > >
