[QUOTE=mikeyakame;3353927]ideal nb gtlref for standard Intel values is 0.666x vTT, but there is an extra value for the NB called FSB_SWING which is 0.25x vTT nominal, this is set by the manufacturer and it determines the distance for logical 0 / 1 from gtl ref voltage. it's the swing distance for a switched voltage. It may be that this is based off a divider from the GTLREF NB voltage which has already been reduced by a set of 1% resistors, it would make sense to do something along these lines as too high a vTT would cause too large swing between ground and power, perhaps thats the reason why we use smaller NB GTLREF multipliers or values.
Bookmarks