CM5 Ethernet Switch

"Power Stage Placement" completed.

flux

Action 4 remains blocked: safe correction of the placed terminal metadata could not be verified, so no design changes were made. Fresh checks still show three Missing Power errors—U1 VBUS_EN/VBAT and U2 VDD12_SW_OUT—plus the incorrect U2/L2 association; placement and copper checks remain clear, with details in ERC Metadata Remediation.
Shall I proceed with action 5’s routing-constraint review only, keeping routing and geometry changes paused until the stackup is resolved?
D

dgobc

ok

flux

I’ll review the PCIe, RGMII, and Ethernet routing constraints only—pair definitions, impedance targets, timing/length requirements, and reference planes. I won’t change geometry or start routing while the stackup remains unresolved.
Thought for 17 mins 9 sec
Thought for 17 sec
Awaiting 1 task
"PCB Routing Constraint Review" completed.

flux

The routing-constraint review reported completion, but I could not retrieve its findings before tool access ended, so action 5 is not yet reconciled or verified.
This session requested a read-only review; no board edits or routing were applied by me. Next is to retrieve the report, assess its PCIe/RGMII/Ethernet findings, and present the results for your approval before any further action.
Execution stopped because your ACUs ran out.

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Files

Pins

Symbol

Layout

3D View

PCB Placement Report
Scope Status

Table

ItemStatusResult
Core CM5 → LAN7431 → KSZ9477 placementCompletedU1, U2, and U3 placed as a compact left-to-right signal chain with U2 PCIe-facing orientation and U3 RGMII-facing orientation.
Six MagJack support groupsCompletedJ1–J6 were not moved; their CT capacitors and LED resistors were grouped immediately behind their owning connectors with central escape space preserved.
Ethernet decoupling and bulk placementCompletedC30–C80 moved to bottom-side perimeter rings around U2/U3; bulk and bias/reset/strap support placed locally.
25 MHz clock placementCompletedY1/C86/C87 and Y2/C88/C89 placed adjacent to their IC clock pins.
Input/power groupingCompletedExisting protection and regulator stages were consolidated into compact upper-board groups; J7 remained unchanged and accessible.
RoutingUnattempted (out of scope)No traces or vias were added, removed, or rerouted.
Footprint-internal copper cleanupFailed / blocked68 pre-existing overlapping-copper errors remain inside the U2/U3 exposed-pad footprint constructions; placement cannot correct internal footprint geometry.
Final Key Coordinates
Coordinates are board-centered millimetres; rotations are counter-clockwise.

Table

RefFunctionX (mm)Y (mm)Rotation
U1Compute Module 5-60.0014.00270°
U2LAN7431 PCIe Ethernet controller-11.50-18.0090°
U3KSZ9477 managed switch9.00-14.00180°
Y1LAN7431 25 MHz crystal-2.58-21.720°
Y2KSZ9477 25 MHz crystal21.00-8.500°
J1LAN port 1 MagJack-57.50-48.430°
J2LAN port 2 MagJack-34.50-48.430°
J3LAN port 3 MagJack-11.50-48.430°
J4LAN port 4 MagJack11.50-48.430°
J5LAN port 5 MagJack34.50-48.430°
J6WAN MagJack57.50-48.430°
J7DC barrel input-75.0045.000°
J812 V terminal input15.0041.950°
U4Input protection/eFuse27.0032.000°
U55 V regulator47.0033.000°
U6Regulator stage72.0033.000°
U7Regulator stage-15.0048.000°
U8Regulator stage25.0050.000°
Placement Distance Summary

Table

RelationshipApproximate resultTarget / interpretation
Y1 centre to nearest U2 XI/XO pin5.2 mmMeets the ≤6 mm crystal target.
Y1 to C86 / C87 centres2.8 mm / 3.0 mmLoad capacitors are immediately adjacent to the crystal.
Y2 centre to nearest U3 XI/XO pin3.6 mmMeets the ≤6 mm crystal target.
Y2 to C88 / C89 centres3.5 mm / 3.2 mmLoad capacitors are immediately adjacent to the crystal.
U1 body edge to U2 body edge15.6 mmCompact PCIe chain with a clear routing corridor.
U2 body edge to U3 body edge6.7 mmShort RGMII channel with usable escape width.
U2 0603 bypass centre to package edgeapproximately 0.9–2.3 mmConsistent with close per-pin bypass placement.
U3 0603 bypass centre to package edgeapproximately 1.4–2.4 mmConsistent with close per-pin bypass placement; bottom placement preserves top escape.
MagJack support parts behind connector bodyapproximately 4.5–8.5 mmLocal CT/LED grouping while leaving the pair escape corridor open.
Functional Grouping
  • J1: C90–C93, R17, R30
  • J2: C94–C97, R18, R19
  • J3: C98–C101, R31, R32
  • J4: C102–C105, R33, R34
  • J5: C106–C109, R35, R36
  • J6: C110–C113, R37, R38
  • U2 bypass ring: C38–C41, C63–C70, C74–C80 on Bottom
  • U3 bypass ring: C30, C31, C33–C62, C71–C73 on Bottom
  • U2 clock: Y1, C86, C87
  • U3 clock: Y2, C88, C89
Verification Evidence
  • Final placement-specific DRC review found no component-body overlap, component-outside-board, keepout, edge-placement, or pad-access-clearance violations.
  • Final crystal-loop and decoupling-placement review returned no error or warning results.
  • Connectivity inspection confirmed the preserved logical chains:
    • PCIe nets between U1 and U2, including TX, reference clock, reset, clock request, wake, and receive-side source nets.
    • RGMII TX/RX buses and clocks between U2 and U3.
    • LAN1–LAN5 MDI nets from U3 to J1–J5.
    • WAN MDI nets from U1 to J6.
    • LAN7431_XI/XO through Y1/C86/C87 and KSZ9477_XI/XO through Y2/C88/C89.
  • No schematic connections, net names, footprints, stackup, board outline, or layout rules were changed.
Remaining Pre-existing Errors
The DRC still reports 68 overlapping-copper errors, exactly the same count observed before placement work. The UIDs identify internal footprint elements rather than inter-component placement collisions:
  • U2 LAN7431: exposed pad EP overlapping internal thermal-via/mount elements.
  • U3 KSZ9477: exposed/ground pad element c852966a...ed2e9677 overlapping numerous internal footprint mount elements.
These errors require correcting or replacing the U2/U3 footprint constructions; moving components cannot resolve them. The board is also intentionally unrouted, so the existing airwire report remains outside this placement-only task.

  • Scope Status

  • Final Key Coordinates

  • Placement Distance Summary

  • Functional Grouping

  • Verification Evidence

  • Remaining Pre-existing Errors