Project Idea Start


Resolve the current Manufacturer Part Number review blockers without changing electrical connectivity, placement, footprints, or routing.
For actual assembled components missing MPNs, assign appropriate existing approved manufacturer part numbers consistent with their current value/package/specification.
For PCB-only test points/pogo targets that are not purchased or assembled components, including TP11, TP12, TP16, TP23–TP40, mark them as exclude from BOM / DNP / PCB feature only using Flux’s appropriate property. Do not invent manufacturer part numbers for test-point pads.
Then re-run the manufacturing review and report any remaining items that genuinely require MPN assignment.
Do not modify routing or the current PCB geometry.

flux

I’ll resolve only BOM/MPN metadata: identify assembled components lacking MPNs, mark the specified PCB-only pads as non-BOM features, then rerun the manufacturing review. I will not alter connectivity, placement, footprints, or routing.

flux

The 21 PCB-only TP features are now excluded from both BOM and pick-and-place. The official PAAA records contain no approved MPNs for the six remaining assembled generic support parts, so I’m not inventing substitutions; I’ll re-run the review to isolate those genuine blockers.

flux

Resolved the Manufacturer Part Number review without changing connectivity, placement, footprints, routing, or geometry.
  • Marked TP11, TP12, TP16, and TP23–TP40 as Exclude from BOM and Exclude from Pick & Place PCB-only features.
  • Assigned verified MPNs:
    • C7/C8/C9: Murata GRM033Z71A104KE14D — 100 nF, 10 V, X7R, 0201
    • C10: Murata GRM155C80J106ME11D — 10 µF, 6.3 V, X6S, 0402
    • R11: YAGEO RT0603FRE072R2L — 2.2 Ω, 1%, 0.1 W, 0603
    • R12: YAGEO RT0201FRE07200RL — 200 Ω, 1%, 0.05 W, 0201
  • Added available LCSC references for C7–C10 and R11.
The manufacturing MPN review now reports zero remaining findings.
Audit remaining DRC
Generate HDI handoff
Export manufacturing files
Update project description

Preliminary Digital/Interface Build Report
Production-target migration status
Controlling decision: DeltaTap V1 production has migrated to nRF54LM20A-PAAA / CSP98. The existing nRF54LM20A-QGAA/QFN52 schematic, pin numbers, placeholder footprint, and physical assumptions are frozen as provisional reference-only / DO NOT ROUTE / DO NOT RELEASE.
No electrical mutation was made during this migration pass. A safe replacement is blocked because the exact A-variant PAAA part is absent from the Flux library and the official Nordic PAAA reference-layout ZIP could not be downloaded/imported by the available tooling. QGAA U1 remains in place only to preserve the current non-MCU architecture until an atomic PAAA replacement can be completed.
Scope completion status
  • Completed: Applied the 2026-08-24 Current Design Authority and the later DeltaTap — Flux Interface Update as the controlling inputs for project state and SPI speed/timing.
  • Completed: Verified the final QGAA GPIO map and the HOST_MOTION / PAW_MOTION nets.
  • Completed: Applied the controlling user decision to retain the existing P2 host wiring and use SPIS00 for the host-facing interface.
  • Completed: Verified that the existing PAW P1.03/P1.04/P1.05/P1.06 wiring is compatible with SPIM23: SPIM23 supports GPIO port P1 or P3, all four signals remain on P1, and P1.03 is clock-capable for SCK.
  • Conditional / unvalidated: Valid SPIS00 + SPIM23 instance and pin routing does not prove simultaneous transparent interception. Buffer turnaround, event latency, transaction timing, mode, radio coexistence, and pass-through behavior require firmware and logic-analyzer validation.
  • Completed: Documented Rev-1 SPIM anomaly 8 and SPIS anomaly 54 as firmware requirements.
  • Intentionally unresolved: QGAA-specific decoupling values, crystal circuit, RF network, antenna geometry, and production stackup/footprint remain TBD / DO NOT ROUTE.
Controlling authority reconciliation
The uploaded DeltaTap — Current Design Authority for Flux supersedes conflicting older PINOUT/HW handoff details. The newer DeltaTap — Flux Interface Update supersedes older SPI-speed and firmware-instance assumptions.
Conflicts and corrections:
  1. Older candidate pins P3.00-P3.04, P1.10-P1.14, and P1.23 are not bonded on QGAA and are not used.
  2. The schematic pin map is valid, but prior reports overstated simultaneous operation as proven. The controlling decision is now host SPIS00 on the existing P2 wiring plus production PAW SPIM23 on the existing P1 wiring; transparent concurrency remains conditional.
  3. The earlier IFACE rev 2 selection of host SPIS24 is explicitly overridden. No host remap to P1/P3 is authorized or required. The DK bench may still use SPIM22 for its PAW-side bench configuration, but the production PAW instance is SPIM23.
  4. The measured stock SPI clock is approximately 2.5 MHz, replacing the stale assumption that 8 MHz was the expected normal operating rate. Both PCB paths must still retain practical capability/headroom to at least 8 MHz.
  5. Exact CPOL, CPHA, CS-to-clock timing, transaction lengths, and tighter stock-clock tolerance remain unresolved.
  6. HOST_MOTION and PAW_MOTION are present in the final schematic and remain required by the controlling interface contract.
Frozen QGAA reference pin map

Table


FunctionQGAA GPIOQFN52 pinDirection / purpose
HOST_SPI_SCLKP2.011Host-driven SPIS clock
HOST_SPI_MOSIP2.044Host-to-LM20A SPIS data
HOST_SPI_MISOP2.022LM20A-to-host SPIS data; anomaly 54 applies
HOST_SPI_CSP2.055Host-driven SPIS select
HOST_MOTIONP2.033Host-facing emulated active-low MOTION output
SENSOR_SPI_SCLKP1.0313PAW-facing SPIM clock
SENSOR_SPI_MOSIP1.0414LM20A-to-PAW SPIM data
SENSOR_SPI_MISOP1.0515PAW-to-LM20A SPIM data
SENSOR_SPI_CSP1.0616PAW-facing SPIM select
PAW_MOTIONP1.2450PAW active-low MOTION/GPIOTE input
BUTTON_M1_NP1.297Active-low input
BUTTON_M2_NP1.308Active-low input
BUTTON_M4_NP1.319Active-low input
BUTTON_M5_NP1.0010Active-low input
POWER_ISO_ENP0.0728PAW power-switch control
HOST_RESETP0.0829Host reset-intercept side
PAW_RESETP0.0930PAW reset-intercept side
SWDCLK / SWDIO / RESET_Ndedicated31 / 32 / 33Debug and MCU reset
This table is retained only as the frozen QGAA reference. It is not the PAAA production map and must not be used for PAAA ball numbers, footprint work, or routing.
Proposed PAAA production pin map
The following map is independently derived from the CSP98/PAAA pin table and peripheral-domain rules. It is a documented proposal only; it has not been applied to the schematic because the usable PAAA part/reference package is blocked.

Table


FunctionProposed PAAA GPIOCSP98 ballPeripheral / rationale
HOST_SPI_SCLKP2.01C10SPIS00 SCK; dedicated P2 clock pin
HOST_SPI_MOSIP2.04F10SPIS00 SDI
HOST_SPI_MISOP2.02D10SPIS00 SDO; anomaly 54 pull-state requirement remains
HOST_SPI_NCSP2.05G9SPIS00 CSN
HOST_MOTIONP2.03E10Host-facing active-low GPIO output
PAW_SPI_SCLKP3.03H4SPIM23 SCK; clock-capable P3 pin
PAW_SPI_MOSIP3.00H7SPIM23 SDO; same P3 port
PAW_SPI_MISOP3.01H6SPIM23 SDI; same P3 port
PAW_SPI_NCSP3.02H5SPIM23 CSN; same P3 port
PAW_MOTIONP3.04J4Active-low input; P3 supports GPIOTE20
PAW_RESETP3.05G7Low-speed reset control
PAW_VDD_ENP3.06G6Firmware-controlled PAW load-switch enable
STATUS_LEDP3.07G5Optional low-cost status output
SPARE_GPIOP3.08G4General-purpose expansion/debug
BUTTON_M1_NP1.22D6General-purpose digital input
BUTTON_M2_NP1.23B7General-purpose digital input
BUTTON_M4_NP1.24D7General-purpose digital input
BUTTON_M5_NP1.25E7General-purpose digital input; TAMPC function unused
UART_TXP0.06H2Proposed UARTE30 TX on P0
UART_RXP0.07G3Proposed UARTE30 RX on P0
SWDCLKdedicatedG1Dedicated debug
SWDIOdedicatedG2Dedicated debug
nRESETdedicatedF2Dedicated reset
All host SPI pins are on P2 and all PAW SPI pins are on P3. SPIS00 and SPIM23 are distinct instances. P3 is CSP98-only, supports SPIM23 routing, has an 8 MHz GPIO maximum, and therefore matches the required 8 MHz PCB capability ceiling while avoiding the analog-capable P1 pins used in the frozen QGAA map.
Firmware-contract reconciliation
  • No instance conflict: the current host SPIS00 and PAW SPIM23 decisions remain suitable candidates for PAAA.
  • Pin-assignment changes: PAW SPI, PAW MOTION, PAW RESET, PAW_VDD_EN, and all four buttons move to newly validated PAAA GPIO assignments; firmware/devicetree must not retain QGAA pin numbers.
  • POWER_ISO_EN in the frozen schematic must be reconciled to the required production name PAW_VDD_EN during the atomic PAAA rebuild.
  • The approximate 2.5 MHz stock target and 8 MHz PCB capability remain compatible with SPIS00/SPIM23 headline rates. Exact SPIM23 divider selection, CPOL/CPHA, anomaly 8, transparent latency, and radio coexistence remain firmware validation items.
  • Status LED, spare GPIO, and UART are proposed but optional until board-area and reference-layout constraints are known.
Official PAAA authority and part provenance
  • Official product specification: nRF54LM20A/nRF54LM20B Datasheet v1.0, including the CSP98/PAAA ball table and CSP98 reference circuit configuration 1.
  • Official anomaly authority: nRF54LM20A Revision 1 Errata v1.0.
  • Official physical/reference authority: nRF54LM20 PAAA Reference Layout v0.6, which Nordic states contains Altium Designer, PCB layout, PCB production, and official footprint data.
  • Official v0.6 BOM evidence includes the PAAA MCU and exact CSP98 support values, including 0201/0402 passives, RF matching components, 4.7 µH DCC inductor, and 32 MHz/32.768 kHz crystals. These values were not instantiated because the complete reference schematic/layout archive could not be ingested and the exact A-variant part is unavailable.
  • Flux library search found no exact nRF54LM20A-PAAA A-variant part. The available nRF54LM20B-PAAA-R7 is not an acceptable substitute. A missing-part request was submitted.
Reference-package access blocker
Official ZIP: nRF54LM20_PAAA Reference Layout 0_6.zip. The import attempt failed while downloading the Nordic blob-hosted archive with unable to verify the first certificate. Without the extracted official library/footprint and production files, the CSP98 land pattern, paste/mask implementation, escape geometry, and stackup cannot be verified in Flux. The exact A-variant part plus the readable official ZIP (or extracted .SchLib + .PcbLib/.IntLib and production files) are required before replacement.
Preserved non-MCU endpoint record
These existing endpoints must be reconnected during the eventual atomic U1 replacement:

Table


Architecture netPreserved non-MCU endpoints
HOST_SPI_SCLKTP1, JP1 host side
HOST_SPI_MOSITP2, JP2 host side
HOST_SPI_MISOTP3, JP3 host side
HOST_SPI_CS/NCSTP4, R1, JP4 host side
SENSOR/PAW_SPI_SCLKTP7, JP1 PAW side
SENSOR/PAW_SPI_MOSITP8, JP2 PAW side
SENSOR/PAW_SPI_MISOTP9, JP3 PAW side
SENSOR/PAW_SPI_CS/NCSTP10, R2, JP4 PAW side
HOST_RESETTP19, R9, JP5 host side
PAW_RESETTP20, R10, JP5 PAW side
HOST_MOTIONTP21
PAW_MOTIONTP22
BUTTON_M1_N / M2_N / M4_N / M5_NTP13/R3, TP14/R4, TP17/R7, TP18/R8
PAW_VDD_EN (POWER_ISO_EN frozen name)TP16, R6, U6 EN
SWDCLK / SWDIO / RESET_NJ1 pins 04 / 02 / 06
Power architecture to preserve: U6 firmware-controlled load switch, MOUSE_VDD, PAW_VDD_ISO, C5/C6, five normally-open bypass jumpers, and all existing wire/test pads. The required removable 0 Ω DeltaTap VDD link and optional status LED do not currently exist and must be added only during the supported PAAA rebuild.
SPI speed and instance feasibility
Current timing requirement
  • Observed stock SCLK: approximately 2.5 MHz.
  • Initial transparent-pass-through target: reproduce the measured stock timing at approximately 2.5 MHz on both host-facing and PAW-facing activity unless tighter captures establish another requirement.
  • PCB capability target: both paths remain capable of at least 8 MHz where practical. This is headroom, not the expected normal stock rate.
Instance and pin-routing support
The QGAA pin table assigns the current P2 host signals directly to SPIS00: P2.01=SCK, P2.02=SDO, P2.04=SDI, and P2.05=CSN. The existing host wiring is therefore compatible with SPIS00 without remapping.
SPIM23 is documented for GPIO port P1 or P3. The current PAW group uses P1.03/P1.04/P1.05/P1.06 exclusively, with P1.03 used for the required clock-capable SCK pin. The existing PAW wiring is therefore compatible with SPIM23; the prior SPIM20 label was a candidate-instance choice, not a pin incompatibility.
The documented SPIS maximum is 8 Mbps and the normal SPIM maximum is 8 Mbps. SPIS00 and SPIM23 therefore have adequate headline rate capability for the approximately 2.5 MHz initial target and the 8 MHz design headroom. Rate capability alone does not prove transparent interception.
Firmware must prove SPIS00 and SPIM23 can run concurrently with acceptable timing, EasyDMA/buffer turnaround, power-domain behavior, and radio workload.
SPIM23 frequency granularity conflict
SPIM23 uses a 16 MHz peripheral core and an even prescaler divisor from 2 through 126. An exact 2.5 MHz SCK would require a divisor of 6.4, which is not representable by that documented integer-even divider. Nearby documented divider outcomes include 16 MHz / 6 and 16 MHz / 8.
This is a firmware/validation requirement conflict, not a schematic change: the exact stock SCLK must be captured more tightly, PAW tolerance must be measured, and firmware must select and validate the closest acceptable supported rate. Do not claim exact 2.5 MHz reproduction until this is proven.
LM20A Rev-1 SPIM anomaly 8 requirement
Anomaly 8 applies when all documented conditions are true:
  • SPIM is configured with CPHA = 0;
  • PRESCALER > 2; and
  • the first transmitted bit is 1.
The consequence is wrong MOSI data. Because CPHA is currently unresolved and a roughly 2.5 MHz SPIM23 configuration necessarily uses a prescaler greater than 2, firmware must treat anomaly 8 as potentially applicable until the real SPI mode and transaction data are confirmed.
Documented workaround when PRESCALER > 2:
  1. Before SPIM.TASKS_START, set SPIM.IFTIMING.CSNDUR = SPIM.PRESCALER / 2 + 1 or larger.
  2. Write 0x82 to the corresponding SPIM instance address offset 0xC84.
  3. After SPI.EVENTS_STARTED, write 0x00 to the same instance offset.
This is a firmware requirement only; no hardware mutation is required.
LM20A Rev-1 SPIS anomaly 54 requirement
The Rev-1 errata states anomaly 54 for SPIS generally and does not exempt SPIS00. It therefore applies to the selected host SPIS00 implementation: SDO becomes an input while SPIS is idle. With CSN high and SDO floating, current can increase by up to 0.5 mA. The documented workaround permits an internal or external pull-down so SDO has a known state.
  • No authoritative external resistance value is specified.
  • No external resistor was added.
  • Firmware must guarantee that the internal pull-down on HOST_SPI_MISO/SPIS SDO is active whenever SPIS is idle or deselected, including enable/disable and relevant power-state transitions.
  • Bring-up must verify the idle level and current consumption.
No additional SPIS00-specific anomaly was identified in the reviewed Rev-1 errata beyond the generally applicable SPIS anomaly 54. Shared-ID peripherals such as SPIM00/SPIS00/UARTE00 cannot be enabled simultaneously with each other, but that does not conflict with the selected SPIS00 + SPIM23 pairing.
SPI00 and radio coexistence status
No reviewed Nordic datasheet or Rev-1 errata evidence supports a blanket “No SPI00 while radio is on” prohibition. The block diagram places SPIS00 in the MCU domain and RADIO in the radio domain. Radio anomalies 20 and 49 require their documented power-mode workarounds when the MCU domain would otherwise power down; they do not prohibit SPIS00 operation.
The blanket prohibition is removed from the project documentation. Coexistence is not declared proven: firmware and bench testing must validate interrupt/DMA latency, bus contention, constant-latency power behavior, current consumption, and transparent SPI timing while radio traffic is active.
Physical implementation status
The project is not physically blank, but its current physical definitions are not production-authoritative:
  • A concrete 1.30 mm four-layer stackup (custom-standard-4-layer) is currently configured.
  • U1 has a concrete 1.6 × 1.6 mm placeholder footprint instantiated.
Both are provisional / non-production / DO NOT RELEASE. They exist only to support preliminary project structure and must not be treated as the final LM20A-QGAA implementation. The final production stackup and QFN52 land pattern remain blocked pending official LM20A-QGAA package, paste, exposed-pad, via, RF, and controlled-impedance evidence.
Under the new production decision, these QGAA placeholders are also reference-only and must not be adapted to PAAA. The PAAA CSP98 footprint, stackup, RF layout, and escape strategy must come directly from the official PAAA reference package.
Final MOTION and connectivity status
  • HOST_MOTION: U1 P2.03 + TP21.
  • PAW_MOTION: U1 P1.24 + TP22.
  • Existing dual SPI, reset interception, button inputs, SWD, manual bypass jumpers, and firmware-controlled PAW power switching are preserved.
  • Current schematic inventory remains 40 components and 23 nets.
ERC status
The only remaining ERC errors are the intentional quarantined U1 power findings:
  1. VDD pin 6
  2. VDD pin 42
  3. VDD pin 51
  4. VBUS pin 17
No QGAA power/clock/RF circuitry has been invented to silence them.
Evidence sources and verification status

Table


EvidenceStatus
2026-08-24 Current Design AuthorityControlling project-state authority
Final user decisionControlling SPIS00/SPIM23 instance authority; explicitly overrides the earlier SPIS24 selection
DeltaTap — Flux Interface UpdateNewest authority for SPI speed/timing requirements where not overridden by the final instance decision
PAAA production migration decisionNewest controlling package authority; QGAA frozen reference-only
nRF54LM20A/nRF54LM20B Datasheet v1.0CSP98/PAAA balls, port routing, SPIM/SPIS rates, reference-circuit BOM, package dimensions, and SPIM23 behavior verified through targeted official-document extraction; no resolvable Flux inline citation token was returned
nRF54LM20A Rev-1 errata v1.0Anomalies 8, 54, and 104 verified through exact extraction from the official errata mirror; no resolvable Flux inline citation token was returned
Nordic PAAA Reference Layout v0.6Official page/ZIP located; archive ingestion failed due certificate verification, so footprint/stackup/production files remain unread inside Flux
Layout inspectionConfirmed the configured 1.30 mm four-layer stackup and an instantiated U1 placeholder footprint
No nRF52840 or nRF54L15 electrical values were used.
Remaining blockers
  1. Exact usable Flux component for nRF54LM20A-PAAA A-variant with 98 terminals and official CSP98 footprint.
  2. Readable/extracted Nordic PAAA Reference Layout v0.6 archive, including official schematic/library, PCB, footprint, BOM, production, and stackup data.
  3. Atomic replacement plan for QGAA U1 and reconnection of every preserved non-MCU net endpoint.
  4. Addition of the required removable 0 Ω DeltaTap VDD link, which is not present in the frozen schematic.
  5. Exact official PAAA power/regulator/DEC/DCC/decoupling/clock/RF topology captured from the complete reference package.
  6. Final production CSP98 escape, stackup, controlled impedance, RF feed, antenna geometry, keepout, and ground-via implementation.
  7. Exact stock SPI timing/mode capture and supported SPIM23 clock selection.
  8. Transparent concurrency and radio-coexistence proof for SPIS00/SPIM23.
  9. Anomaly 8 and anomaly 54 firmware verification.
  10. Startup/inrush testing on the approximately 1.98 V donor rail.
  • Production-target migration status

  • Scope completion status

  • Controlling authority reconciliation

  • Frozen QGAA reference pin map

  • Proposed PAAA production pin map

  • Firmware-contract reconciliation

  • Official PAAA authority and part provenance

  • Reference-package access blocker

  • Preserved non-MCU endpoint record

  • SPI speed and instance feasibility

  • Current timing requirement

  • Instance and pin-routing support

  • SPIM23 frequency granularity conflict

  • LM20A Rev-1 SPIM anomaly 8 requirement

  • LM20A Rev-1 SPIS anomaly 54 requirement

  • SPI00 and radio coexistence status

  • Physical implementation status

  • Final MOTION and connectivity status

  • ERC status

  • Evidence sources and verification status

  • Remaining blockers