Re: Software based character UART using Yacc (Bison) grammar ...

[Hans Aberg]

On 28 Sep 2005, at 04:24, Jamie Risk wrote:

> I've been trying to develop a small software based character UART.
> Eight (8) bit characters have one start bit (a zero) one stop bit  
> (a one) and one odd bit of parity.  Idle states are a one, so  
> getting 100's of ones in a row is acceptable.  The acceptable  
> format is:

Bison is not built for the kind of problem. You might be able to do  
it with Flex. For example, you could have a loop scanning for the  
first '0', and when it arrives, you set a start condition for a rule  
picking down the next ten characters. If there is something wrong  
with them, put them back, and rescan; otherwise output re character.

  Hans Aberg