Data output impedance control

摘要

The present invention provides an apparatus and method for monitoring the functioning of a special operational mode on an integrated circuit module without the need for a special or dedicated pin. By monitoring the data output pins of the module operation in a special operational mode and premature interruption thereof, is detected. Delayed transition from a state of low impedance to a state of high impedance during the data output cycle is indicative of the special operational mode. The modules which usually have tri-state devices on their output lines are provided with delay circuitry to delay the transition of the tri-state device, during the data output cycle, from a state of low impedance to a state of high impedance while the device remains in a special operating mode.