Hi all, Iam beginner in board design. Iam having one doubt in pull up resistance. If i give pull up in any cmos gate or ttl gate input, what it will take the whether it is 0 or 1 or... 1. what is pull up? 2. Can i drive pull up for any cmos or ttl device for logic 1. is it correct? 3. In i2c protocol SCL and SDA both are open drain? if not why SCL is pull up? 4. what is intermediate voltage range for cmos devices and ttl devices? plz answer anybody best regards, raguraman __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu