HSERIN HSEROUT 9BIT & PARITY (Output is Losing a bit!)

[tumbleweed]

The hardware uart can't do 9E1... that would require 10 bits.

[retepsnikrep]

Maybe I mislead you then, sorry I mean 8,E,1 (1 start bit, 8 data bits, 1 parity bit and one stop bit)

The below sort of works just moving the 9th bit and the 8 Bit data straight across from the RX to TX.

The receiving device is now accepting the input but Saleae logic still shows errors in the data the PIC is outputting???
Something weird is going on..

Start:						'Main program start    

   do while PIR1.5 = 0                        'Wait for RX  data
   loop   
   
   do while PIR1.4 = 0                        'Wait for TX to be ready
   loop
   
   TXSTA.0 = RCSTA.0
   TXREG = RCREG
	
goto start

[HenrikOlsson]

The receiving device is now accepting the input but Saleae logic still shows errors in the data the PIC is outputting???
Something weird is going on..

If you still have the protocol decoder set to 9E1 then I believe that would be the problem since the output from the PIC is 8E1 (11bits total). Likely the input is 8E1 as well, don't you think?

[retepsnikrep]

Yes but setting the decoder to 8E1 on the input gives parity errors. ???

Attached is some logic 1.2.40 data. The top line is the incoming data.

Perhaps some kind soul could have a look at it and see what they make of it.
Have I got the baud rate/parity etc right for the incoming data decoder?
I've tried loads of variations!!

The shortest pulse is about 20us

Note the output data is now at least the same length as the input and the receiving device seems to accept it, but the output decoder with the same settings as the input gives errors!!!

LogicData.zip

[tumbleweed]

If you set both channels of the protocol decoders to 8 data bits, odd parity, 1 stop then the errors go away (8O1), but I don't know about the data.

Are you sure about the format? You don't include the parity bit in the count of data bits. Typical formats would be 8N1, 8E1, or 8O1.
Normally, in 9-bit mode there's no parity used (9N1).

[HenrikOlsson]

Yeah, like tumbleweed says, it does seem to be ODD parity, not EVEN.

[retepsnikrep]

I think you are both right. Thanks a lot.
I had tried lots of combos!!! But missed odd parity...