On Tue, Apr 29, 2003 at 10:33:31AM -0700, Michael Park wrote:
> Please check my understanding of serial i/o:
> If I look at the voltage at the TX pin when the pic sends a byte via its
> usart, I should see a high going low for the start bit, then a bunch of ups
> and downs, then it should go high for the stop bit and stay that way.  Do I
> have that right?

Yes.

>
> Between the start and stop bits, does high mean 0 or 1?

1.

>
> Is there some bit in the pic that inverts the levels?

No. And since EIA-232 (RS-232) inverts the signals (1 is -12V, 0 is 12V)
some sort of external inverter is required for the hardware USART.

BAJ

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