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Preliminary specification

MCN-1

A pre-silicon, two-die wireless microcontroller system-in-package. The compute die carries the application and security cores. The radio die carries a 400 MHz RISC-V baseband core, dual-band Wi-Fi 6, Bluetooth 5.4 LE, and the RF Compliance Firewall.

2 application cores · QFN-56, 7 × 7 mm


Compute

Two application cores

The MCN-1 uses two 400 MHz RV32 application cores. A separate always-on security core runs at 100 MHz and can burst to 400 MHz for post-quantum operations.

Security

Owner controlled root of trust

Customers can use their own secure-boot keys instead of relying on Mericron to authorize firmware. Hybrid secure boot, measured boot, attestation, and rollback protection remain available.

Radio

Dedicated 400 MHz radio core

A 400 MHz RV32 baseband core with 256 KB SRAM runs the open Wi-Fi 6 MAC and Bluetooth 5.4 LE controller.

01 · Compute

CPU subsystem

The FPGA prototype demonstrates concurrent security, application, and radio domains with bus-level access isolation at 50 MHz. PMP/ePMP, world-ID tagging, and IOPMP remain production-silicon enforcement targets.

CPU subsystem
Application cores2× 32-bit RISC-V
Application core frequency400 MHz (max)
Security core1× 32-bit RISC-V, always-on island
Security core frequency100 MHz island; up to 400 MHz burst for PQC operations
Radio baseband core1× RV32IMC at 400 MHz on the radio die
Application pipeline4-stage, in-order
Radio-core memory256 KB SRAM, no cache
ISA extensionsApplication: I, M, A, C, B, Zkn/Zks; security and radio: RV32IMC-class
Memory protectionPMP / Enhanced PMP (Smepmp)
DMA isolationIOPMP on all DMA-capable masters
Interrupt controllerRISC-V CLIC
DebugJTAG/SWD with owner-controlled debug authentication
02 · Memory

Memory

Memory regions
RegionSizeNotes
Boot ROM64 KBImmutable mask ROM with published source and build recipe
Secure SRAM64 KBSecurity-core only; parity and scrub
Main SRAM768 KBPMP/IOPMP-partitioned
L1 cache (per app core)16 KB instruction + 16 KB dataSoftware-managed coherency model
Radio SRAM256 KBCode and packet buffers on D2
In-package flash (option)8 / 16 MBAES-XTS; package feasibility pending
eFuse / OTP8 KB on D1Owner/vendor keys, anti-rollback counters, and SKU configuration
Regulatory eFuseD2-localRegulatory key and anti-rollback state; not writable by D1
03 · Security

Security subsystem

Root-of-trust and physical-hardening entries describe production silicon. FPGA-demonstrated boot, measurement, and attestation results are identified separately.

Root of trust
Device identityPUF; implementation choice is deferred to the test chip
Entropy sourceTRNG per NIST SP 800-90B with continuous health tests
Key storage8 KB D1 OTP plus 64 KB security-core SRAM
Boot ROM64 KB immutable mask ROM with deterministic published build
Boot & attestation
Boot chainMulti-stage, ROM-anchored
Bootloader signatureEd25519 + ML-DSA-87 hybrid; both must verify
Firmware authorityOwner root-key enrollment with Mericron firmware authority revocable by the owner
MeasurementSHA-3-384 extended into on-die PCRs
Anti-rollbackMonotonic OTP counters
AttestationSecurity-core-signed quote over SHA3-384 PCR measurements
Side-channel

DPA / EM countermeasures

Masked AES and lattice-cryptography datapaths, security-island clock controls, and an active shield over key registers and the PUF.

Fault injection

Glitch protection

Voltage-glitch detector, clock-integrity monitor, redundant secure-boot decision logic, and a dual-redundant secure-boot decoder.

Tamper / probing

Physical hardening

Bus scrambling, key-whitened secure SRAM, and an active top-metal shield, subject to 22FDX implementation feasibility.

04 · Crypto

Cryptographic accelerators

Target production services from the always-on security subsystem. Ed25519 and ML-DSA-87 verification plus SHA3-384 measured boot have been proven in the hardware prototype.

Accelerator blocks
AlgorithmTarget implementationStandard
AES-256 (GCM/XTS)DPA-masked hardware pathFIPS 197
SHA-2 / SHA-3Hardware-backed hashing and measured bootFIPS 180-4 / 202
HMAC + HKDFSecurity-core serviceRFC 2104 / 5869
ECDSA P-384Classical signature serviceFIPS 186-5
Ed25519 / X25519Classical signature and key-agreement serviceRFC 8032 / 7748
ML-KEM-1024Planned masked NTT acceleratorFIPS 203
ML-DSA-87Masked accelerator planned for silicon; firmware verification demonstrated on FPGAFIPS 204
SLH-DSAFirmware fallbackFIPS 205
TRNGContinuous health tests; production raw access disabledSP 800-90B
05 · Radio

Wireless / RF subsystem

This section describes intended production silicon. Integrated RF and the open Wi-Fi/Bluetooth firmware stack have not been demonstrated in the FPGA prototype.

Wi-Fi
StandardIEEE 802.11ax (Wi-Fi 6); 802.11a/b/g/n/ac compatible
Topology1×1 single-stream
Bands2.4 GHz + 5 GHz (dual-band)
Key 802.11ax featuresOFDMA, TWT (Target Wake Time), BSS coloring
SecurityWPA3
Front-endOn-die PA, LNA, and switch
2.4 GHz Tx power+20 dBm (on-die)
5 GHz Tx power+16 dBm (on-die)
FirmwareOpen upper/lower MAC and PHY-control firmware; no opaque runtime blobs
Bluetooth
VersionBluetooth 5.4 LE
LE features1M/2M/coded PHY, extended advertising, PAwR, and EAD
CoexistenceDocumented on-die PTA with firmware-visible priority controls
06 · I/O

Peripherals & I/O

Interfaces
InterfaceQuantityNotes
GPIO38Secure-world-lockable bits
UART4
SPI31× octal-capable high-speed interface
I²C2
I²S2
CAN-FD2External transceivers required
USB1USB 2.0 Full-Speed device + host
Ethernet MAC0Deliberately omitted in v1; Ethernet is used only by the hardware development platform
ADC8-channel12-bit
DAC212-bit
PWM12
RTC1Always-on wake source
Watchdog3Windowed, independent, and security watchdogs
07 · Fabric

Clocking & interconnect

Core clocks
Application cores400 MHz
Security core100 MHz island; up to 400 MHz PQC burst
Radio baseband core400 MHz
System fabric
D1 crossbar64-bit AXI-lite-class at 200 MHz
Isolation metadataWorld-ID tagged, with IOPMP on DMA-capable masters
Die-to-die link2 Gbps effective source-synchronous link
Always-on domainIndependent security and RTC clocking
08 · Power

Power & operating conditions

These are architecture budgets, not characterized silicon values. The security core owns the power-management policy.

Recommended operating conditions
ParameterMinTypMaxUnit
Supply voltage (VDD)3.03.33.6V
Operating temperature (industrial)−40+105°C
Power architecture budgets
StateCurrent budgetDomains alive
Active, 2 cores + radio idle≤30 mAD1
Modem sleep (Wi-Fi associated, TWT)≤1.5 mA averageSecurity core + radio timers
Light sleep≤200 µASecurity island + SRAM retention
Deep sleep (RTC + 32 KB retained)≤25 µASecurity island
Hibernate≤8 µARTC + wake logic
09 · Package

Package, process & quality

The baseline plan targets GlobalFoundries 22FDX at Fab 8 in Malta, New York. This is a manufacturing target, not an announced foundry contract. U.S. packaging and test partners remain under qualification.

Package & mechanical
ConstructionTwo-die system-in-package: D1 compute + D2 radio
PackageQFN-56, 7 × 7 mm wettable-flank SiP
Package fallback8 × 8 mm LGA if QFN-56 package feasibility does not close
ProcessGlobalFoundries 22FDX planned for both dies
Optional memory8 / 16 MB flash die stacked on D1 or external-only launch
Customer interfaceOne package, one part number, one reflow footprint
Quality & compliance direction
Operating temperature−40 °C to +105 °C
Automotive qualificationNot part of the v1 launch scope
FIPS 140-3Roadmap item; not a general-availability blocker and not yet validated
Origin documentationPer-SKU supply-chain origin statement planned
10 · Evidence

Architecture proven in prototype.

Working hardware validates the digital trust boundaries and boot architecture. Integrated RF, package, power, and production performance remain pre-silicon targets.

Demonstrated architecture
AreaDemonstrated resultScope
Multicore boundarySeparate security, application, and transport domains execute concurrentlyDigital architecture
Boot and attestationHybrid verification, measured boot, and signed attestation operate end to endSecurity architecture
RF policyRadio activation is gated by RF Compliance Firewall authorizationPolicy enforcement model
Positioning

A current-generation comparison.

Compare MCN-1 with current wireless MCU options from leading semiconductor vendors. This is a positioning comparison, not a benchmark.

Positioning comparison
Specification
Selected competitor ESP32-S31
MCN-1 preliminary target
Application processing 2× 32-bit RISC-V at up to 320 MHz + 1× low-power RISC-V at 40 MHz 2× 32-bit RISC-V at 400 MHz + dedicated security and radio cores
Wi-Fi Wi-Fi 6, 2.4 GHz; 20 MHz in 802.11ax mode and 20/40 MHz in legacy modes Wi-Fi 6, 2.4/5 GHz, 20/40/80 MHz
Bluetooth and 802.15.4 Bluetooth 5.4 LE and Classic; Zigbee and Thread Bluetooth 5.4 LE; no 802.15.4 in v1
Internal SRAM 512 KB shared + 32 KB low-power SRAM; 16/32 MB in-package PSRAM variants 768 KB main + 64 KB secure + 256 KB radio SRAM
Package and GPIO QFN-80, 8 × 8 mm; 60 GPIOs QFN-56 two-die SiP, 7 × 7 mm; 38 user GPIO target
CAN 1× CAN-FD controller compatible with ISO 11898-1:2015 2× CAN-FD controllers
Wireless firmware model Open-source ESP-IDF application framework with Espressif-supplied wireless components Planned open, reproducibly buildable, owner-flashable Wi-Fi and Bluetooth firmware
Security model Secure boot, flash and PSRAM encryption, PUF-backed key manager, TEE/APM and anti-DPA cryptography Dedicated security core, owner root keys, measured boot, attestation, and hybrid classical plus post-quantum boot target
Silicon process Process node and wafer fabrication site are not stated publicly GlobalFoundries 22FDX for both dies; Fab 8 is the baseline target, not an announced contract
Developer experience Mass production since July 2026; ESP-IDF v6.1+ support remains comparatively new Open SDK, Zephyr-first workflow, examples, and migration guides remain in development

ESP32-S31 values are from Espressif's pre-release Series Datasheet v0.5 and July 2026 mass-production announcement. MCN-1 values are preliminary architecture targets. Integrated RF, power, package, and production performance remain uncharacterized.

Production silicon values on this page are preliminary architecture targets unless explicitly identified as demonstrated on the FPGA prototype.

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