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trying to grasp clocks


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I'm trying to make the launchpad talk serial at 57600 or 19200 baud. i tried reading slaa322b, but it mostly passed over my head and the only think i learned from it is that everything will go wrong if i use a crystal...

 

but let's go... first thing i noticed is that even 19200 is more than half the 32760. Can i hope to do anything useful at 0.589x my max clock?

 

I'm still unsure how the clock relates to the cpu instruction cycle... i gathered there's the cpu bound clock at 32khz, and an optional peripheral clock that can go up to 100mhz... but i think those other clocks are moot for me since i'm caring about code in the cpu anyway...

 

i'm coming from platforms that run at full power and the cpu clock is king. this is really weird for me... i'm not even understanding if my G2231 has a 32khz clock or if it's the one i have to solder on the board. If it's the one i have to solder i think my fun with the msp430 will end here because i will not do that. (well, i will try, and destroy both component and the board in the process. that's what i mean by i will not do it. and before you try to say it's easy, keep in mind i can't solder speaker wires correctly)

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If you are thinking on TUSB launchpad uart there is another topic about this...

http://www.43oh.com/forum/viewtopic.php?f=8&t=3208

 

If you are thinking on MSP430F2xx or MSP430G2xx used on board, some of them have USCI uart channel and can go over 115200 bps. If they don't have it, it can be emulated by software, and again it can go over 115200 bps.

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The g2231 has an internal clock generator that can supply up to 16mhz main clock (MCLK). There is an internal sub clock that can be a division of that main clock (SMCLK) and a third clock that can be a division of the main clock or sourced from the external lftx1 crystal. (ACLK) some of the peripherals can further subdivide these clocks down also. In general M and SM clock are high speed, high power usage, and A clock is low speed low power (the high power clocks cam be shutoff for "sleep" mode to save power.

 

Hope this helped, i would go into more detail but im on my cellphone and its hard to type long stuff

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