Forum - MCS Electronics

 

FAQFAQ SearchSearch RegisterRegister Log inLog in

pull up resistors with TWI higher speeds

 
Post new topic   Reply to topic    www.mcselec.com Forum Index -> Various
View previous topic :: View next topic  
Author Message
hgrueneis

Bascom Member



Joined: 04 Apr 2009
Posts: 856
Location: A-4786 Brunnenthal

austria.gif
PostPosted: Thu Aug 04, 2011 8:13 pm    Post subject: pull up resistors with TWI higher speeds Reply with quote

Further experimenting with TWI clock speeds of about 800 KHz (by setting the registers directly) I have noticed that a perfect waveform on the clock signal does not work so well. A much higher pull up value is needed on the clock than on the data line.
I used 1 to 2 Kohm on data but 4K7 on the clock, then it works fine. Adapting the pullup with scope to a perfect
50% duty clock did not work.
Hope this helps a bit.
Also the new slave lbx for TWI is much faster than pushall/popall of course because there are not as many registers saved.
Hubert
Back to top
View user's profile
Display posts from previous:   
Post new topic   Reply to topic    www.mcselec.com Forum Index -> Various All times are GMT + 1 Hour
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum