Edson Brusque wrote...

>    I'm using the internal 4MHz clock of the 16F628 on a device that sends
>and receives serial data at 9600bps. As usual, SPBRG=25 and BRGH=1, but I've
>noticed that the USART is running at a higher data rate then the expected
>9600baud.
>
>    To confirm my thoughts, I took the multimeter (to measure frequency) and
>got 9984bps. This is a diference of 3,8%!

(rest snipped)

My copy of the PIC16F628 datasheet, DS40300B on page 139 shows the INTRC
frequency as being 4.00 MHz typical, 3.65 MHz minimum, and 4.28 MHz
maximum- an uncertainty of -9% to +7%.

Dave D.

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