On Wed, Jun 10, 2009 at 3:25 PM, JMGross<[email protected]> wrote: > > My own experiences with the UART programming is that the internal RC clock is > way too unstable and exact to produce a stable communication. > With 4MHz RC clock I was unable to establish a reliable link with 9600 Baud, > while with the same code and an external 8 MHz quarts even a baudrate of > 115KBaud was no problem. > At least you'll need an external 32KHz clock-quartz and some timer-driven > code to build something like a software-PLL to keep the RC oscillator in the > proper range. > > JMGross
Were you using the calibrated clock? "Internal Frequencies up to 16 MHz With Four Calibrated Frequencies to ±1% " <- from msp430f22x2 datasheet. Later on in the datasheet it claims ±2.5% over frequency, still close enough for reliable async comms. If the frequency is off, it's off -- the baudrate makes no difference. Regards, Mark markra...@gmail -- Mark Rages, Engineer Midwest Telecine LLC [email protected]
