In this paper, we describe a frame-interleaving hardware architecture for a generalized node-based successive cancellation list (SCL) decoder. By efficiently reusing otherwise idle computational units, two independent frames can be decoded simultaneously, resulting in a significant throughput gain. Based on this new architecture, we also exploit graph ensembles to diversify the decoding, enhancing the error-correcting performance by 0.28 dB and reducing the worst-case latency for serial graph processing by over 32%. Implementation results show that the proposed SCL decoder with frame-interleaving architecture achieves a throughput of 7.15 Gbps and an area efficiency of 37.63 Gbps/mm2, which is 1.56× and 1.11× better than the state-of-the-art node-based SCL decoders.