SENT / LIN

Two independent, clean-room BFMs — written from the public SAE J2716 SENT and LIN 2.x specifications, not from the catalog’s own sent/lin RTL — serve as a true second source for both protocols. The SENT BFM drives a full sync-pulse + status + data-nibble + CRC-4 frame on the timed tick grid the receiver expects; a passive checker independently re-decodes the falling-edge period stream and re-computes the CRC-4, catching an injected bad CRC nibble that the DUT’s own error path also flags. The LIN BFM is a full node — BREAK/SYNC/PID/DATA/CHECKSUM framing in both directions — proven against the catalog lin in both roles: as an independent master driving the DUT-as-slave capture path (classic and enhanced checksum), and passively decoding the DUT operating as its own master over a real wired-AND bus. A passive checker independently re-validates BREAK-field minimum length and checksum, catching both an injected bad checksum and an injected too-short break field. Building this VIP also caught and led to fixing a real lin RTL bug (2026-07-09): the RX-buffer SECDED check-bit array wasn’t cleared alongside the data buffer on a new frame, so switching from a longer frame to a shorter one without an intervening reset could latch a spurious double-bit-error safety fault against stale check bits — fixed by clearing the check-bit array at the same points the data buffer itself is cleared, verified against the IP’s full existing regression, cover, and k-induction proof coverage plus this VIP’s own interop TB. Scope today is the core frame shape for each: SPC trigger mode and automatic baud-rate detection / wake-sleep signaling are documented roadmap items, not yet built.

Key Features

• Independent SENT sensor BFM: SAE J2716 sync + status + data-nibble + CRC-4 frame generator on a configurable tick grid, plus a bad-CRC error-injection primitive
• Independent LIN 2.x node BFM: full BREAK+SYNC+PID+DATA+CHECKSUM master framing (classic/enhanced) and a passive frame listener, plus bad-checksum and too-short-break injection primitives
• Passive protocol checkers for both: SENT nibble-period legality + independent CRC-4 cross-check; LIN BREAK-length legality + independent checksum cross-check — all wire-level, never reading DUT-internal state
• Self-checking interop TB against the catalog sent/lin: SENT RX-path decode; LIN slave-capture (classic + enhanced) and DUT-as-master generation over a real wired-AND bus — all pass; this second-source effort also caught and fixed a real stale-SECDED-check-bit safety-fault bug in lin (2026-07-09)

Standards & Compliance

SAE J2716 (SENT), LIN 2.x

Pairs With

Built to lean against these catalog IPs during integration:

• sent
• lin