A packaged integrated circuit device includes a substrate, and a conductive pad and a chip stack on the substrate. A primary conductive line electrically connects the pad on the substrate to a conductive pad on one of the chips in the chip stack. Secondary conductive lines electrically connect the pad on the one of the chips to respective conductive pads on ones of the chips above and below the one of the chips in the chip stack. The primary conductive line may be configured to transmit a signal from the pad on the substrate to the pad on the one of the chips in the chip stack, and the secondary conductive lines may be configured to transmit the signal from the one of the chips to the ones of the chips thereabove and therebelow at a same time.