A Time-Division Multiplexing Signaling Scheme for Low-Power Multi-Drop Memory Links

A time-division multiplexing (TDM) digital channel coding scheme for wireline multi-drop interfaces has been proposed. Shaping the TX spectrum to avoid channel frequency notches, the proposed digital TDM signaling reduces inter-symbol interference (ISI) and far-end crosstalk (FEXT) in multi-drop bus (MDB) interfaces. Thanks to a proper guard interval insertion, the transmitted signal exhibits reduced inter-channel interference (ICI) among time-domain sub-channels, as compared to the previously proposed digital spectrum shaping signaling. Applying the proposed coding scheme, the data rate (DR) can be 4 times higher than the first channel notch frequency, without employing decision-feedback equalizer (DFE), feed-forward equalizer (FFE) and continuous-time linear equalizer(CTLE). However, non-return to zero (NRZ) signaling necessitates DFE with at least 12 taps on the receiver (RX) side for receiving data at the same rate.