A 3D stacked electro-optical radiation imaging device with a plurality of integrated circuit layers, the device having a pixelated array of semiconductor detector elements, in which each detecting element is electrically connected a stacked integrated circuit. The stacked integrated circuit has a mixed signal layer and a reconfigurable layer. The mixed signal layer has a passive signal path and an active signal path. A readout decoder block controls operation of the passive paths. The active signal path triggers readout upon transient event detection and is readout by an address arbitration control block, the address arbitration control block operating independent and asynchronous to the readout of the passive path and transient event detection initiates the identification of the location of and readout of the signaling active path. The reconfigurable layer has processing units that each correspond to one or more pixels in the pixelated array. The processing units are reconfigurable through received signals from either the passive path, the active path, or an external signal. A controller programs and communicates with the mixed signal layer and reconfigurable layer