Monolithic three dimensional (3D) integrated circuits (ICs) (3DICs) with vertical memory components are disclosed. A 3D memory crossbar architecture with tight-pitched vertical monolithic intertier vias (MIVs) for inter-block routing and multiplexers at each tier for block access is used to shorten overall conductor length and reduce resistive-capacitive (RC) delay. Elimination of such long crossbars reduces the RC delay of the crossbar and generally improves performance and speed. Further, elimination of the long horizontal crossbars makes conductor routing easier. The MIVs, with their small run-length, can work without the need for repeaters (unlike the long crossbars), and control logic may be used to configure the memory banks based on use.