Analysis of Echo and Crosstalk Cancellation in Simultaneous Bidirectional Transceivers for Dense Die-to-Die Interconnects

The impact of echo and crosstalk cancellation in die-to-die interconnect links that employ simultaneous bidirectional (SBD) signaling is analyzed in the context of a 24-wire transceiver operating over a four-layer interposer. Simulation results show that these techniques allow for a 4-rank transceiver system with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$40\mu m$</tex> bump pitch to occupy only <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$240\mu m$</tex> die edge width and signal up to 128Gb/s per data channel wire over a very tight <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$4\mu m$</tex> signal-to-signal pitch, resulting in a 46.9Tb/s/mm edge density. The proposed crosstalk cancellation circuitry improves the inbound signal voltage margin at 32GHz by 22% at a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{BER} =10^{-12}$</tex>.