Motor, Power & Sensor Control

Fan Tachometer + PWM Speed Controller

fansensor reads a fan tachometer to report speed (period + cumulative edge count), flags a stalled fan,

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ASIL-B

target

93.00%

SPFM

90.00%

LFM

PASS

FMEDA

1.6K

gates

1.0.0

version

The deliverable

What you’re licensing

fansensor reads a fan tachometer to report speed (period + cumulative edge count), flags a stalled fan, It is delivered as a licensable soft-IP block engineered as an ASIL-B Safety Element out of Context — not just RTL, but the complete functional-safety work package needed to carry it into an ISO 26262 program:

Synthesizable RTL

Portable, vendor-neutral SystemVerilog that drops onto your existing SoC fabric — no foundry or EDA-tool lock-in.

Per-IP FMEDA report

SPFM / LFM / PMHF computed against the ASIL target per ISO 26262-5 — the quantitative analysis your assessor asks for.

Safety manual

Assumptions of use, the safety mechanisms and their diagnostic coverage — written to drop straight into your safety case.

IP-XACT + integration docs

A machine-readable descriptor plus register and integration documentation for fast, low-risk bring-up.

Self-checking testbench

A self-checking (crypto: bit-exact) testbench and a one-command build, so you can reproduce every claim on day one.

fan_sensor reads a fan tachometer to report speed (period + cumulative edge count), flags a stalled fan, and—for 4-wire fans—generates the PWM control signal.

Key Features

Pulse-count tachometer with configurable gate window
RPM calculation from pulse count + reference clock
Stall detection and under-speed interrupt
PWM duty-cycle fan drive output
Primary counter independent DMR lockstep (err_code 9)
Config-register parity (err_code 1)

Standards & Compliance

Generic (4-wire PWM fan, IPMI FRU spec tach-pulse polarity)

Functional Safety

ASIL-B (SEooC) · SPFM 93.00% · LFM 90.00% · PASS

ISO 26262:2018 · FMEDA available · Safety Manual included

Register Map

Offset	Register	Description
`0x00`	CTRL	[0]=EN [1]=MODE(0=4w,1=3w) [2]=PWM_EN 0x04 PWM_PERIOD 0x08 PWM_DUTY
`0x0C`	TACH_PERIOD(RO)	0x10 TACH_COUNT(RO) 0x14 STALL_TIMEOUT
`0x18`	STATUS	[0]=stall [1]=tach_valid [2]=spinning (RO) 0x1C IER

Getting Started

// Minimal instantiation
fan_sensor #(
  .ADDR_W(6)
) u_fan_sensor (
  .clk       (clk),
  .rst_n     (rst_n),
  // APB4
  .p_paddr   (paddr),
  .p_psel    (psel),
  .p_penable (penable),
  .p_pwrite  (pwrite),
  .p_pwdata  (pwdata),
  .p_prdata  (prdata),
  .p_pready  (pready),
  // Safety
  .err_clear (1'b0),
  .err_valid (err_valid),
  .err_code  (err_code)
);

Configure via the CTRL register after reset to enable the IP and set operating parameters. Monitor err_valid / err_code for any safety faults reported by the built-in safety monitor.

Applications

Where it fits

Typically deployed in motor drives, power conversion, and sensor front-ends in automotive and industrial systems.

The case

Why license it, not build it

Skip 12–18 months

The FMEDA and the safety case are already generated. You integrate a finished safety element — you don’t stand up a safety-IP program to originate one.

One vendor, one safety story

Every block in the catalog shares the same safety architecture, fault-reaction model, and FMEDA methodology — so subsystems roll up cleanly.

Verified, not vapor

The RTL builds and passes today; the safety metrics come from analysis and fault injection against real RTL, not a datasheet promise.

Interested in Fan Tachometer + PWM Speed Controller?

Pricing, the per-IP FMEDA, safety manual, and RTL data room are shared under a mutual NDA.

Talk to us →See related IP

Figures are pre-silicon engineering-grade estimates for a Safety Element out of Context (SEooC); final ASIL sign-off is the integrator’s, supported under NDA. FMEDA and Safety Manual available under NDA.

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