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Cortex-M3 Processor

The ARM Cortex™-M3 processor is the industry-leading 32-bit processor for highly deterministic real-time applications, specifically developed to enable partners to develop high-performance low-cost platforms for a broad range of devices including microcontrollers, automotive body systems, industrial control systems and wireless networking and sensors. The processor delivers outstanding computational performance and exceptional system response to events while meeting the challenges of low dynamic and static power constraints. The processor is highly configurable enabling a wide range of implementations from those requiring memory protection and powerful trace technology to cost sensitive devices requiring minimal area.


Why Cortex-M3

Delivering higher performance and richer features

Introduced in 2004 and recently updated with new technologies and configurability, the Cortex-M3 is the mainstream ARM processor developed specifically with microcontroller applications in mind.

Performance and Energy Efficiency

With high performance and low dynamic power consumption the Cortex-M3 processor delivers leading power efficiency 12.5 DMIPS/mW based on 90nmG. Coupled with integrated sleep modes and optional state retention capabilities the Cortex-M3 processor ensures there is no compromise for applications requiring low power and excellent performance.

Full featured

The processor executes Thumb®-2 instruction set for optimal performance and code size, including hardware division, single cycle multiply, and bit-field manipulation. The Cortex-M3 NVIC is highly configurable at design time to deliver up to 240 system interrupts with individual priorities, dynamic reprioritization and integrated system clock.

Rich connectivity

The combination of features and performance enables Cortex-M3 based devices efficiently to handle multiple I/O channels and protocol standards such as USB OTG (On-The-Go).



The Cortex-M family is an ideal solution for ranges of compatible, easy to use embedded devices such as microcontrollers (MCU) where different cost, power and performance considerations must be made. Each processor delivers an optimal trade-off for a broad embedded application range.

Cortex-M family processors are all binary upwards compatible, enabling software reuse and a seamless progression from one Cortex-M processor to another.


STM32 - 32-bit ARM Cortex MCUs

The STM32 family of 32‑bit Flash microcontrollers based on the ARM Cortex™‑M processor is designed to offer new degrees of freedom to MCU users. It offers 32‑bit product range that combines high performance, real‑time capabilities, digital signal processing, and low‑power, low‑voltage operation, while maintaining full integration and ease of development.

The unparalleled and large range of STM32 devices, based on an industry-standard core and accompanied by a vast choice of tools and software, makes this family of products the ideal choice, both for small projects and for entire platform decisions.


STM32 F1 Mainstream

The STM32 F1 is a series of mainstream MCUs covering the needs of a large variety of applications in the industrial, medical and consumer markets. With this series of products, ST has pioneered the world of ARM® Cortex™-M microcontrollers and set a milestone in the history of embedded applications. High performance with first-class peripherals and low-power, low-voltage operation is paired with a high level of integration at accessible prices with a simple architecture and easy-to-use tools. The series consists of five product lines which are pin-to-pin, peripheral and software compatible.

  • Value line STM32F100 - 24 MHz CPU with motor control and CEC functions
  • Access line STM32F101 - 36 MHz CPU, up to 1 Mbyte Flash
  • USB access line STM32F102 - 48 MHz CPU with USB FS
  • Performance line STM32F103 - 72 MHz, up to 1 Mbyte Flash with motor control, USB and CAN
  • Connectivity line STM32F105/107 - 72 MHz CPU with Ethernet MAC, CAN and USB 2.0 OTG

STM32 F1 series of mainstream MCUs

STM32 L1 Ultra Low Power

Based on the Cortex™-M3 core running at 32 MHz and ST’s proprietary ultra-low-leakage process, the STM32 L1 series offers a wide portfolio in features, memory size and package pin count. The STM32 L1 and the well-know STM8 L1 are both members of the ultra-low-power family and share the same ultra-low-leakage process technology developed by ST.

The STM32 L1 series combines ultra-low power and performance. The portfolio covers from 32 to 384 Kbytes of Flash memory (up to 48 Kbytes of RAM and 12 Kbytes of true embedded EEPROM) and from 48 to 144 pins. The series is available in 3 different lines: STM32L151 (no LCD), STM32L152 (LCD), STM32L162 (LCD and AES-128). This innovative architecture (voltage scaling, ultra-low-power MSI oscillator) gives your design more performance for a very low power budget. The large number of embedded peripherals, such as the LCD interface, op-amp, comparator, ADC, DAC and AES, gives it a very high level of integration for all your needs.

To ease your migration and give you all the flexibility you need, the STM32L is pin-to-pin compatible with the STM32F and opens the door to the full STM32 ecosystem.

  • Low power mode: down to 300 nA
  • Dynamic run mode: down to 230 μA/MHz


  • ARM Cortex‐M3 32 MHz CPU
  • 32 to 384 KFlash, up to 48K SRAM and up to 12K EEPROM
  • Three lines: pin‐to‐pin, software and peripheral compatibility
  • Pin‐to‐pin compatibility with STM32F series (except VBAT not present on the STM32L)
  • Ultra‐low energy consumption: down to 180 μA/DMIPS from Flash
  • Supply voltage: 1.65 to 3.6 V

Six ultra‐low‐power modes: down to 300 nA

  • Ultra‐low‐power dynamic modes: low‐power run down to 9 μA; low‐power sleep down to 4.9 μA with one timer
  • Economical Run mode consumption down to 230 μA/MHz from Flash at zero‐wait state with dynamic voltage scaling (3 ranges)
  • Rich set of high‐end analog and digital peripherals
  • ‐40 to +85 °C operating temperature range
  • STM32L151 standard family
  • STM32L152 has an additional LCD-segment driver
  • STM32L162 embeds a 128-bit AES
  • Supply monitoring and resets
    • Full reset circuitry, supply monitoring
    • Power‐on reset & Power‐down reset, permanently enabled (zero power)
    • Brown‐out detection (BOR) can be on or off in low‐power modes
    • BOR complies with all VDD rise/fall times, so no constraints on power supply shape.
    • When BOR is not activated, the STM32L starts at VDD = 1.65 V.
    • Programmable voltage detection can be on or off
  • Extended battery lifetime down to 1.65 V



  • STM32L151 standard family
  • STM32L152 has an additional LCD-segment driver
  • STM32L162 embeds a 128-bit AES



Power-Saving Features and Benefits

The STM32L lines propose 6 different ultra‐low‐power modes to offer users a high level of flexibility depending on their application. In addition, the dynamic run consumption has been optimized.

  • Low‐power run mode:
    CPU is still running Execution is done from RAM with a low‐speed oscillator (RTC or internal) Consumption is 9 μA typical
  • Low‐power sleep mode
    offers the possibility of keeping the RTC and a few other peripherals active (such as the timer) with a consumption of 4.9 μA typical with one timer activated. The Flash is switched off and the regulator is put into ultra‐low‐power, the CPU is stopped, the RTC and peripherals can be activated.
  • Stop modes (2 modes)
    The CPU, main clocks and peripherals are off
    The RTC can be on or off (2 modes)
    Wake up can be done through an interrupt on the peripherals SRAM and context are kept
  • Standby modes (2 modes):
    The CPU, main clocks and peripherals are off
    The RTC can be on or off (2 modes)
    Backup registers are preserved
    Wake up can be done through wake‐up pins




  1. STM32L Standard Library
  2. STM32L Touch-Sensing Library
  3. STM32L1 ultra-low-power 32-bit MCU series

Application Notes, Manuals, etc

  1. Application Notes are here
  2. Programming Manuals are here
  3. Technical Notes are here
  4. User Manuals are here
  5. Errata Sheets are here

STM32 F2 Hi-Performance

The ARM® Cortex™-M3-based STM32 F2 series is built on ST’s advanced 90 nm NVM process technology with the innovative adaptive real-time memory accelerator (ART Accelerator™) and the multi-layer bus matrix offering an unprecedented price/performance trade-off.

This series is characterized by a high degree of integration combining up to 1 Mbyte of Flash memory and up to 128 Kbytes of SRAM with Ethernet MAC, USB 2.0 HS OTG, camera interface, and hardware encryption support and external memory interface.

ST‘s acceleration technology enables these MCUs to achieve up to 150 DMIPS at 120 MHz FCPU which is equivalent to zero wait state execution, while keeping the dynamic current consumption at the outstandingly low level of 188 µA/MHz.

The devices are available in LQFP64, LQFP100, LQFP144, WLCSP64 (< 4 x 4 mm), UFBGA176 and LQFP176 packages.

STM32 F2 series of high-performance MCUs

STM32 F4 Hi-Performance & DSP

The ARM® Cortex™-M4-based STM32 F4 series is an extension of the industry-leading STM32 portfolio towards even higher performance. Like the STM32 F2 series, these MCUs leverage ST‘s 90 nm NVM technology and ST’s ART Accelerator™ to reach the industry’s highest benchmark scores for Cortex-M-based microcontrollers with 210 DMIPS/469 Coremark executing from Flash memory at 168 MHz operating frequency.

The DSP instructions and the floating point unit enlarge the range of addressable applications.

The STM32 F4 series is the result of a perfect symbiosis of the real-time control capabilities of an MCU and the signal processing performance of a DSP, and thus complements the STM32 portfolio with a new class of devices, digital signal controllers (DSC).

The STM32 F4 series remains pin-to-pin and software compatible with the STM32 F2 series and features more SRAM, peripheral improvements such as full duplex I²S, improved RTC and faster ADCs.

The devices are available in LQFP64, LQFP100, LQFP144, LQFP176 and UFBGA176 packages.

STM32 F4 series of high-performance MCUs with DSP and FPU instructions

STM32 F0 Entry-level

The ARM Cortex-M0 based STM32 F0 series delivers 32-bit performance and the essential DNA of the STM32. The STM32 F0 benefits from the combination of real-time performance, low-power operation, advanced architecture and peripherals associated to the STM32 ecosystem.

The new series bridges the gap with applications using 8- and 16-bit microcontrollers, enabling advanced high-end features in economical end products. The STM32 F0 series offers unparalleled flexibility and scalability for home-entertainment products, appliances, and industrial equipment.

STM32 F0 devices are available in UFQFPN32, LQFP48 and LQFP64 packages.

STM32 F0 series Entry-level Cortex™-M0 MCU

STM32 F3 Analog & DSP

The STM32 F3 series of microcontrollers combines a 32-bit ARM Cortex-M4 core with a DSP and FPU instructions running at 72 MHz with advanced analog peripherals for more flexibility. This series innovates in embedded DSC design by combining a Cortex-M4 core with fast 12-bit 5 MSPS and precise 16-bit sigma-delta ADCs, programmable gain amplifiers (4 gains, 1% accuracy), fast 50 ns comparators and versatile time control units running at 144 MHz, giving optimum integration.

The STM32 F3 series allows designers to tackle mixed-signal control applications. The devices are optimized for efficient handling and processing of mixed signals in circuits such as 3-phase motor controllers, biometrics and industrial sensor outputs or audio filters. They help simplify design, cut power consumption and reduce PCB size in consumer, medical, portable fitness, system monitoring and metering applications.

Pin compatible with the STM32 F1 series, the new STM32 F3 series enlarges the STM32’s Cortex-M4 portfolio which now offers both entry-level cost with the F3 series and highest performance with the F4 series. The STM32 F3 series includes devices with 64 to 256 Kbytes of on-chip Flash memory, up to 48 Kbytes of SRAM and is available in WLCSP66 (less than 4.3 x 4.3 mm), LQPF48, LQFP64, LQFP100 and UFBGA100 packages.

STM32 F3 series of mixed-signal MCUs with DSP and FPU instructions

STM32W Wireless

The STM32 family has been extended to the IEEE 802.15.4 wireless network domain bringing outstanding radio and low-power microcontroller performances.

  • Embedded 2.4 GHz IEEE 802.15.4 radio
  • Best-in-class code density, thanks to its ARM Cortex-M3 core
  • Low-power architecture

It is an open platform with extra resources for application integration:

  • Configurable I/Os, ADC, timers, SPI, UART
  • Main software libraries: RF4CE, IEEE 802.15.4 MAC

With a configurable total link budget up to 109 dB and the efficiency of the ARM Cortex-M3 core, the STM32W is a perfect fit for the wireless sensor network market.

The STM32W series includes devices with 64 to 256 Kbytes of on-chip Flash memory, up to 16 Kbytes of SRAM and is available in VFQFN40, UFQFN48 and VFQFN48 packages.

STM32W series of Wireless MCUs

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