NuMicro^® M3351 series is a family of microcontrollers designed for high performance, 5V power supply operation, and high noise immunity for industrial applications. It is based on the Arm^® Cortex^®-M33 core, with a maximum operating frequency of up to 144 MHz. The series features a complete DSP instruction set and a single-precision floating-point unit (FPU), delivering excellent performance for real-time control, data processing, and multi-communication integration applications.

The M3351 series supports an operating voltage range from 2.7V to 5.5V and an operating temperature range of -40°C to +105°C. It also provides ±4 kV ESD (HBM) protection and ±4.4 kV EFT immunity, making it particularly suitable for applications requiring high stability and noise resistance, such as industrial equipment, smart home appliances, human-machine interfaces, and computer peripherals.

Enhanced Processing Performance

The M3351 series provides up to 1024 KB of dual-bank Flash memory with ECC (Error Correction Code) support, enabling background operation and bank swap to support OTA/FOTA (Firmware Over-The-Air) update requirements.

In addition, the M3351 series features a dedicated 64 KB Data Flash with write protection. It uses an 8 KB page erase unit, offering greater flexibility for parameter data storage and application updates.

To reduce the CPU core workload when accessing peripheral devices, the series also includes up to 12 channels of Peripheral Direct Memory Access (PDMA).

Enhanced Security Features

In terms of security design, the M3351 series supports multiple cybersecurity protection mechanisms. It features Secure Boot and Arm^® TrustZone^®, along with separate secure and non-secure memory access regions. It also includes a pseudo-random number generator (PRNG), a true random number generator (TRNG), and hardware cryptographic accelerators such as AES, SHA, and HMAC-SHA, effectively safeguarding code, keys, and the integrity of the device boot process.

Rich Control Features

In terms of analog and control features, the M3351 series integrates one 12-bit 1.7 Msps SAR ADC, one 14-bit 1.0 Msps SAR ADC, one 12-bit 1.0 Msps DAC, two analog comparators (ACMP), one built-in temperature sensor, and one internal voltage reference generator. It also provides up to 24 PWM output channels and up to two sets of EQEI, meeting the demands of signal acquisition, closed-loop control, and multi-channel driving simultaneously.

Diverse Connectivity Interfaces

The M3351 series also provides a wide range of communication and peripheral interfaces, including two Universal Serial Control Interfaces (USCI) that can be flexibly configured as UART/SPI/I²C, up to 10 x UART, 1 x SPI/I²S, 1 x SPI, 3 x I²C, 1 x I3C, 2 x CAN FD, 1 x QSPI, and 1 x USB 2.0 full-speed Host/Device interface. It also includes 10 x LLSI, 2 x eLLSI, 1 x ECAP, and supports an External Bus Interface (EBI).

The M3351 series is available in multiple package options, including QFN33, QFN48, LQFP48, LQFP64, LQFP100, and LQFP128.

The Nuvoton M3351 NuMaker evaluation board and Nu-Link debugger are powerful tools for product evaluation and development. It also supports IDEs provided by third-party vendors, such as Keil MDK, IAR EWARM, and VS Code.

M3351 series is suitable for a variety of application markets, including：

• Industrial Automation
• Human-Machine Interface
• Communication Systems
• Smart Home Appliances
• Gaming Peripherals

Key Features:

Operating Characteristics

• Voltage range：2.7V ~ 5.5V
• Temperature range：-40°C ~ +105°C
• ESD HBM：±4 kV
• EFT：±4.4 kV
• Latch Up：±200 mA

Core

• Arm^® Cortex^®-M33 core with TrustZone^®, clocked up to 144 MHz
• DSP Instruction Set
• Single-precision floating-point arithmetic instructions (FPU)
• Memory protection unit with 8 memory regions (MPU)

Memories

• Up to 1 MB Flash memory, Dual Bank
• Flash memory with Error Correction Code (ECC)
• Secure Boot ROM (MaskROM)：32 KB
• LDROM Flash：16 KB
• Dedicated 64 KB Flash memory (up to 100,000 write/erase cycles)
• Write protection for APROM, LDROM, and Data Flash.
• SRAM：128 KB with ECC

External memory interface

• External Bus Interface (EBI), supporting 8/16 bit data width and i80 LCD interface

Clocks

• 4~32 MHz External high-speed crystal oscillator (HXT)
• 32.768 kHz External low-speed crystal oscillator (LXT)
• Internal 48 MHz RC oscillator
• Internal 38.4 kHz RC oscillator
• Internal PLL up to 144 MHz

Peripheral Direct Memory Access (PDMA)

• 1 group of 12-channel peripheral direct memory access (PDMA)
• Channels can be triggered by software UART, SPI, PWM, TIMER, ADC, ACMP, and I²C.

Power Management

• Normal run： 87.08 μA/MHz（at 25°C/5.0V）
• Normal power-down mode (NPD2)：219.48 μA （at 25°C/5.0V）
• Standby power-off mode (SPD1) 64 KB SRAM retention：24.13 μA (at 25°C/5.0V)
• RTC（V_BAT）：34 μA
• Support Power-on reset （POR）
• Support Brown-out reset（BOR）
• Support Low voltage reset（LVR）
• Built-in LDO

Timers & Control Peripherals

• 4 sets of 32-bit timers, supporting PWM function
• 2 sets of 24-bit SysTick timers
• 2 sets of Watchdog Timers (WDT)
• 2 sets of Windows Watchdog Timer (WWDT)
• Up to 12 PWM channels
• Up to 12 basic PWM (BPWM) channels
• Up to 2 Enhanced Quadrature Encoder Interfaces (EQEI)
• 1 set of Enhanced Input Capture Unit (ECAP)

Connectivity Interfaces

• Up 10 sets of UART interfaces
• Up to 3 sets of I²C interfaces, up to 3.4 Mbps
• 1 set of I3C interface
• 1 set of SPI/I²S interface
• 1 set of SPI interface
• 1 set of Quad‑SPI interface
• 2 sets of CAN FD interfaces
• 2 sets of enhanced LED strip control interfaces (ELLSI)
• 10 sets of LED strip control interfaces (LLSI)
• 2 sets of Universal Serial Control Interfaces (USCI) configurable as UART, SPI, or I²C

Advanced Connectivity

• USB 2.0 Full‑Speed Device / Host with built‑in transceiver (device mode supports crystal‑less operation)

Analog Peripherals

• 1 set of 12‑bit, 24‑channel, 1.7 Msps SAR ADC
• 1 set of 14‑bit, 16‑channel, 1.0 Msps SAR ADC
• 1 set of 12-bit, 1.0 Msps buffered DAC
• 2 sets of analog comparators (ACMP)
• Built‑in reference voltage (2.56V / 3.072V / 4.096V)
• Built‑in temperature sensor

Security Functions

• Secure Boot
• Crypto accelerator supporting AES‑256, SHA‑256, HMAC-SHA-512 and pseudo random number generator (PRNG)
• True Random Number Generator (TRNG)
• Flash supports up to two eXecute-Only-Memory (XOM) regions

RTC

• Calendar‑type RTC supported

I/O Function

• Up to 106 GPIO pins with interruption capability
• GPIO with built‑in pull‑up / pull‑down resistors

96-bit unique ID (UID)

128-bit unique customer ID (UCID)

Development Environment:

Development board: