Steve Church

9S08QG8 internal clock accuracy

Discussion created by Steve Church on Mar 29, 2007
Latest reply on Mar 29, 2007 by Steve Church
I'm a new user to this chip and want to use it's serial USART for communicating with an external device. I wish to use the internal oscillator as a clock source so that I can use the external clock pins for I/O. I have found that the stability of the internal clock is 2% which should be adequate for serial comms at 19200 baud. What steps do I have to go through to ensure that the internal clock is set correctly. I must admit to being confused by the trim thing. I have always used an external crystal for previous designs but need a couple of extra pins. Does the default internal clock get set to 32kHz? or is this frequency dependant on the trim register?

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