Re: Serial communication, detecting parity bits

On 2006-01-20, Floyd L. Davidson <floyd@xxxxxxxxxx> wrote:

>>My question is this: Is there some way that I can figure out if
>>the wakeup or parity bit was set on a specific byte in the
>>stream that I have read from the serial port?
>
> The "parity bit" is the 8th bit (also called the "high" bit).

Unless it's the 9th bit. There's a chance the device in
question is using 8 data bits "with parity" where that 9th
"parity" bit is used to mark the first byte in a frame.

That's a popular way to use the UART on an 8051
microcontroller: it has support for explicitly settign the
state of the 9th bit and for that 9th bit to cause an
interrupt with it's received as a 1.

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