Circuitry is provided that includes programmable fabric with fine-grain routing wires and a separate programmable coarse-grain routing network that provides enhanced bandwidth, low latency, and deterministic routing behavior. The programmable fabric may be implemented on a top die that is stacked on the active interposer die. The programmable coarse-grain routing network and smart memory circuitry may be implemented on an active interposer die. the smart memory circuitry may be configured to perform higher level functions than simple read and write operations. The smart memory circuitry may carry out command based low cycle count operations using a state machine without requiring execution of a program code, complex microcontroller based multicycle operations, and other non-generic microcontroller based smart RAM functions.