stateless-me/sparrowlink

SparrowLink v1.0

Note

DNA preserved: ultra-compact Fast-Path framing, 64b/66b with self-sync scrambler, credits/ACK/NACK, and ULP power states. Profiles: Short-reach ULP, XR (long-range twinax/fiber), lane bonding (2/4/8×), hot-plug, light FEC, and D2D (die-to-die). Version: 1.0

0) Scope & Profiles

• ULP-10 (base): 10.0 Gb/s useful / lane, ~10 cm PCB/FPC, FEC off
• LR-10 (XR): 10.0 Gb/s / lane, ≤ 30 cm FR-4 or ≤ 1 m passive twinax, light FEC on
• LR-25 (XR): 25.0 Gb/s / lane, ≤ 15 cm FR-4 or ≤ 1 m twinax, light FEC on
• XR-100 m: same protocol over 10GBASE-R/SR fiber via PHY shim
• D2D-SR: in-package/interposer ≤ 20 mm, optional forwarded clock, ultra-low swing, FEC off

Horizontal scaling: 2/4/8× lanes (bonding + deskew).

1) Layering

App ⇄ Link (FPF, credits, selective ACK/NACK, SEQ=256)
   ⇄ PCS 64b/66b (scrambler x^58+x^39+1, AM/IDLE/TS)
   ⇄ PHY shim
        • ULP short reach (NRZ, AC-coupled, 100 Ω)
        • XR long range (NRZ + light FEC / 10GBASE-R fiber)
        • D2D-SR (DC-coupled, low swing, forwarded clock)
   ⇄ Medium (PCB/FPC | twinax | SR fiber | Cat6a via 10GBASE-T PHY)

2) Rates, Timing, Throughput (per lane)

• Coding: 64b/66b ⇒ line = 66 × f_block
• 10G base: f_block = 156.25 MHz ⇒ 10.3125 Gb/s line ⇒ 10.0 Gb/s useful
• Block time (66 b): 6.4 ns (exact)
• Streaming: 8 B / 6.4 ns = 1.25 GB/s useful