Rev A (TTSKY26c silicon)

This commit is the design submitted to the Tiny Tapeout TTSKY26c shuttle, and the fabricated die carries it exactly. The full LibreLane flow on SKY130A signed off clean, with no DRC, LVS, or setup violations, and the complete cocotb suite passed against the hardened gate-level netlist.

Rev B (majority-vote receiver)

Rev B decides each received data, parity, and stop bit by a 2-of-3 majority vote across three oversample points straddling the bit center, so a noise glitch narrower than one oversample period cannot flip a bit or fake a framing error. The change is verified at RTL by sample-point glitch tests that fail on rev A and pass here, by a measured clock-mismatch envelope of -4.63% to +5.56% against the documented +/-4% contract, and by the full pin-level suite.

Rev B is not fabricated. Its extra cells push the 1x2 tile past its routing margin at 77% utilization, so the proven rev A netlist remains on the shuttle.