an ic module , such as a multi - chip module , includes multiple ic dice , each having a test mode enable bond pad , such as an output enable pad . a fuse incorporated into the mcm &# 39 ; s substrate connects each die &# 39 ; s test mode enable bond pad to one of the mcm &# 39 ; s no - connection pins , and a resistor incorporated into the substrate connects the test mode enable bond pads to one of the mcm &# 39 ; s ground pins . by applying a supply voltage to the test mode enable bond pads through the n / c pin , a test mode is initiated in the dice . once testing is complete , the fuse may be blown , and a ground voltage applied to the test mode enable bond pads through the ground pins so the resistor disables the test mode in the dice and initiates an operational mode . as a result , dice packaged in ic modules may be tested after packaging .