An MCU erratum applies to a defined device behavior under stated conditions, often with revision-specific status. Reading the document title alone cannot establish whether a PCB is affected. Connect the installed silicon revision to the peripherals and firmware paths actually used by the product.
STMicroelectronics’ STM32F405/407 and STM32F415/417 errata sheet includes silicon identification and a revision-dependent summary. Use the current errata for the exact device family; similar part names do not establish the same limitations or workarounds.
Establish which revision is present
Follow the manufacturer’s documented identification method, which may involve package information, an identification register, or both. Retain the result with the board or build record at the granularity your process supports. Do not infer every device’s revision solely from the purchase date.
List the product’s enabled peripherals, clocking modes, low-power states, and relevant operating sequences. Include factory programming, bootloader, diagnostics, and service modes, since a limitation may affect these paths even when normal application operation appears unaffected.
Create an applicability table
| Field | Purpose |
|---|---|
| Erratum identifier and document revision | Identifies the reviewed statement |
| Applicable silicon revisions | Defines the potential material population |
| Product trigger conditions | Explains whether the limitation can occur |
| Workaround and verification | Shows how the product addresses the condition |
Record why a limitation is not applicable, such as an unused feature or a prohibited operating sequence. A blank cell is ambiguous: it may mean no impact, no review, or missing evidence. Record assumptions such as an unused peripheral in configuration controls, since a later firmware feature can invalidate the conclusion even when the PCB and component remain unchanged. Route that feature change through the errata review.
Verify the actual workaround
- Locate the implementation in the released firmware or hardware.
- Check that it covers all relevant code paths.
- Exercise the triggering condition where practical and safe.
- Record the tested silicon and software revisions.
- Review behavior when different approved silicon revisions are mixed.
Do not remove a workaround merely because a newer part revision is available. Confirm which revisions the production supply may contain and whether firmware must support both. Conversely, retaining an old workaround may need review if the manufacturer changes its recommendation.
Close the review with an explicit supported revision set and any purchasing or programming restrictions. Revisit the table when the errata, firmware, or approved component changes. The PCN applicability guide explains how manufacturer notices can trigger this review across multiple board revisions rather than only the latest design.
Move from reading to a build-ready project
Use the fabrication and assembly checklists to prepare drawings, production files and test requirements.
Open the DFM checklist