Orcad Schematic Check

OrCAD Schematic Check

Core Rules

• Treat .DSN files as OrCAD/Capture binary design databases, not text files.
• Prefer Cadence 17.4 Tcl DB API for 17.4 designs. Do not save a newer DSN with older Cadence tools.
• Use Windows paths with forward slashes when launching Cadence tools from WSL, such as D:/....
• Always run report before apply.
• Always create a backup before writing.
• Always verify by reopening the DSN in a fresh process after apply.
• Record commands, counts, logs, and pitfalls in the task notes if the user is building a reusable skill.

Available Scripts

The skill bundles deterministic Tcl scripts in scripts/.

• scripts/reset_display_prop_colors.tcl

  • Resets component instance display property colors, including visible Reference, Value, and footprint-like display props, to DboValue_DEFAULT_OBJECT_COLOR.
  • Usage:

    cmd.exe /C D:/3_Software/Cadence/SPB_17.4/tools/bin/tclsh.exe D:/path/to/reset_display_prop_colors.tcl D:/path/to/design.DSN report D:/path/to/report.log
    cmd.exe /C D:/3_Software/Cadence/SPB_17.4/tools/bin/tclsh.exe D:/path/to/reset_display_prop_colors.tcl D:/path/to/design.DSN apply D:/path/to/apply.log
    

• scripts/renumber_references_by_page.tcl

  • Renumbers part Reference values using the leading number in the page name.
  • Usage:

    cmd.exe /C D:/3_Software/Cadence/SPB_17.4/tools/bin/tclsh.exe D:/path/to/renumber_references_by_page.tcl D:/path/to/design.DSN report D:/path/to/report.log nonconforming
    cmd.exe /C D:/3_Software/Cadence/SPB_17.4/tools/bin/tclsh.exe D:/path/to/renumber_references_by_page.tcl D:/path/to/design.DSN apply D:/path/to/apply.log nonconforming
    

Reference Renumber Policy

Before applying reference renumbering, ask the user which policy to use:

• nonconforming: keep references whose numeric portion already matches the current page range, and only assign new numbers to nonconforming references. This is the default and safest policy.
• all: fully resort and renumber every component in each page/prefix group.

For page N, a reference is conforming when its numeric portion is in [N*100, N*100+99]. For example, on page 5, R500 through R599 are conforming.

In nonconforming mode:

• Reserve all already-conforming references first.
• Assign nonconforming references to the first available numbers in the page/prefix range.
• Do not reorder already-conforming references just because schematic coordinates differ.

In all mode:

• Sort part instances by page, prefix, Y coordinate, then X coordinate.
• Assign references from pageNumber * 100, incrementing independently per prefix.

Write Workflow

1. Identify the DSN and Cadence version.
2. Convert WSL paths to forward-slash Windows paths for Cadence commands.
3. Run the script in report mode.
4. Inspect summary counts:
   • For color reset: nonDefault, set, failed.
   • For renumbering: changes, skipped, duplicateExisting, duplicateTargets, failed.
5. If any target reference duplicates or skipped entries need review, stop and explain.
6. Create a timestamped or task-specific backup.
7. Run apply.
8. Run report again in a fresh process against the saved DSN.
9. Confirm the verification target:
   • Color reset: nonDefault=0.
   • Renumbering: changes=0.

Cadence Tcl Pitfalls

• $placedInst SetReference can return success but not persist the value read by $partInst GetReference.
• $partInst SetReference can update the value in session but not make the design save unless the part instance is marked modified.
• After successfully setting a part reference, call:

  $partInst SetOccsModified 1
  $partInst MarkModified
  

• Use temporary references during batch renumbering to avoid mid-apply collisions when two existing references swap values.
• Use DboSession_MarkAllLibForSave and DboSession_SaveDesign, then close and reopen for verification.

Extra Detail

Read references/orcad-capture-dsn.md when adapting scripts, changing Cadence versions, or troubleshooting save/verification mismatches.