Hello,

is it possible to reach more than 9600baud with the
uart and 32,768khz crystal ?
I really need 115200baud and this 32khz crystal.
Is it possible and if yes how much is the difference to
115200baud ?
If not how fast is the communication with I2C bus ?

Thanks a lot.

Regrads,

Gabi

On Sat, May 15, 2004 at 12:23:15PM -0000, buffne01 wrote:
> Hello,
> 
> is it possible to reach more than 9600baud with the
> uart and 32,768khz crystal ?
> I really need 115200baud and this 32khz crystal.
> Is it possible and if yes how much is the difference to
> 115200baud ?
> If not how fast is the communication with I2C bus ?

You need to run the CPU and UART from the DCO (internal RC oscillator) to
get higher speeds. You cannot run at more then 32kbaud with the 32kHz clock
alone (there is no clock multiplier inside the MSP). With the DCO you can
run at e.g.4MHz and work at the higher baud rates. However the DCO is
sensitive to temperature and supply. First you need to calibrate your
routines to run at the proper speed (autobaud). 

You ask for I2C. If you can choose I2C you should go with it. Clock can be
between 0Hz and 100kHz (or higher, depends on you I2C chips). No problem
with the drifting DCO. Speed is quite high. With the on chip I2C hardware
you should be able to reach the speed of the clock. But I think the CPU is
not fast enough to put the bytes to the memory at clock speed ;-). Maybe a
combination between the I2C-hardware and the DMA-unit is able to do that.

What do you want to do? Communication between MSP430's ?

        Matthias