Hi all, We can introduce wired-AND logic by connecting 2 or more open-drain (also open-collector) outputs together with a single pull-up resister. The logic of AND logic results as follows: If one or more of the drivers asserts the output to low state (electrically low ), the equivalent output is low, which is how an AND gate functions. Also the connected signals have to be active-low signals. I have seen many documents refering to the above scenario as wired-OR logic. It doesnt make sense. Also the PCI spec 2.2, sec2.1 refers to O/D signals (ex INTX# and SERR#) as to be capable of introducing wired-OR logic. So what is wired-OR logic? How do we realise this logic? Does the active level of the connected signals make the difference? Also one more question. When it comes to wired-AND logic, only one device can assert its output low. We cannot have more than one device asserting its output low simultaneously. Am i right in saying so. If yes, is this allowed in wired-OR logic. Thanx in advance for all the valuable inputs. Regards, Anand Kuriakose. ------------------------------------------------------------------ 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 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