please dont rip this site

Mike Harrison says:

While we're on the subject of neat little routines etc...

This code sends a byte at 115.2Kbaud
With a 4.096MHZ xtal, error is about 1.25% (near enough),
with 4.000MHz, 4.55% (marginal).

Data is non-inverted (i.e can be fed straight to PC)

txbyte  
  movwf temp
  movlw d'10'  ; 1 start + 8 data + 1 stop
  movwf cnt
  bcf status,c  ;start bit
  movf portb,w
txloop
  andlw 0ff-(1<<seroutbit)
  skpc
  iorlw 1<<seroutbit
  movwf portb
  sec
  rrf temp ; carry shifted in as stop bit
  decfsz cnt
  goto txloop
  return

Incidentally It's also possible to do 115K2 bit-bashed reception at 4.096MHz, by generating an INT interrupt off the startbit edge, and grabbbing all the data bits within the int code. Context save/restore overheads mean there's only a couple of cycles available to the foreground task if data is streaming in continuously!


file: /Techref/microchip/rs232at115kbps.htm, 1KB, , updated: 2000/3/20 11:02, local time: 2020/3/30 00:58,
TOP NEW HELP FIND: 
34.239.172.52:LOG IN

 ©2020 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?
Please DO link to this page! Digg it! / MAKE!

<A HREF="http://www.massmind.org/Techref/microchip/rs232at115kbps.htm"> Mike Harrisons 115.2kBaud with a 4.096Mhz crystal</A>

After you find an appropriate page, you are invited to your to this massmind site! (posts will be visible only to you before review) Just type in the box and press the Post button. (HTML welcomed, but not the <A tag: Instead, use the link box to link to another page. A tutorial is available Members can login to post directly, become page editors, and be credited for their posts.


Link? Put it here: 
if you want a response, please enter your email address: 
Attn spammers: All posts are reviewed before being made visible to anyone other than the poster.
Did you find what you needed?

 

Welcome to massmind.org!

 

Welcome to www.massmind.org!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  .