| 摘要 |
According to one aspect of the invention, a novel control circuit is coupled to a pin at a circuit node. The circuit node has a particular default condition of one of two logic states. The control circuit stores the default value and subsequently attempts to drive an alternate logic state onto the pin. The circuit then reads the logic state at the pin to determine if there has been a change of logic state registered. If a change has been registered, then the existence of a third condition or fourth condition is indicated, depending upon the default logic state.
|
