STM32

STM32 Family ^[1]

Produced	From 2007 to Current
Designed by	STMicroelectronics
Max. CPU clock rate	24  to 216 MHz
Min. feature size	130 to 90 nm
Microarchitecture	ARM Cortex-M7 [2] ARM Cortex-M4F [3] ARM Cortex-M3 [4] ARM Cortex-M0+ [5] ARM Cortex-M0 [6]

STM32 is a family of 32-bit microcontroller integrated circuits by STMicroelectronics. The STM32 chips are grouped into related series that are based around the same 32-bit ARM processor core, such as the Cortex-M7, Cortex-M4F, Cortex-M3, Cortex-M0+, or Cortex-M0. Internally, each microcontroller consists of the processor core, static RAM memory, flash memory, debugging interface, and various peripherals.^[1]

Overview

The STM32 is a family of microcontroller ICs based on the 32-bit RISC ARM Cortex-M7, Cortex-M4F, Cortex-M3, Cortex-M0+, and Cortex-M0 cores.^[1] STMicroelectronics licenses the ARM Processor IP from ARM Holdings. The ARM core designs have numerous configurable options, and ST chooses the individual configuration to use for each design. ST attaches their own peripherals to the core before converting the design into a silicon die. The following tables summarize the STM32 microcontroller families.

STM32 Series	ARM CPU Core
F7	Cortex-M7F
F4, F3, L4, J	Cortex-M4F
F2, F1, L1, W, J	Cortex-M3
L0, J	Cortex-M0+
F0, J	Cortex-M0

History

The STM32 is the third ARM family by STMicroelectronics. It follows their earlier STR9 family based on the ARM9E core,^[7] and STR7 family based on the ARM7TDMI core.^[8] The following is the history of how the STM32 family has evolved.

• In October 2006, STMicroelectronics (ST) announced that it licensed the ARM Cortex-M3 core.^[9]

• In June 2007, ST announced the STM32 F1-series based on the ARM Cortex-M3.^[10]
• In November 2007, ST announced the low-cost "STM32-PerformanceStick" development kit in partner with Hitex.^[11]

• In October 2009, ST announced that new ARM chips would be built using the 90 nm process.^[12]

• In April 2010, ST announced the STM32 L1-series chips.^[13]
• In September 2010, ST announced the STM32VLDISCOVERY board.^[14]
• In November 2010, ST announced the STM32 F2-series chips based on the ARM Cortex-M3 core, and future development of chips based on the ARM Cortex-M4 and ARM Cortex-M3 cores.^[15]

• In February 2011, ST announced the STM32L-DISCOVERY board.^[16]
• In March 2011, ST announced the expansion of their STM32 L1-series chips with flash densities of 256 KB and 384 KB.^[17]
• In September 2011, ST announced the STM32 F4-series chips based on the ARM Cortex-M4F core and STM32F4DISCOVERY board.^[18]

• In February 2012, ST announced the STM32 F0-series chips based on the ARM Cortex-M0 core.^[19]
• In May 2012, ST announced the STM32F0DISCOVERY board.^[20]
• In June 2012, ST announced the STM32 F3-series chips based on the ARM Cortex-M4F core.^[21]
• In September 2012, ST announced full-production of STM32 F3-series chips and STM32F3DISCOVERY board. The STM32 F050-series will also be available in a TSSOP20 package.^[22]

• In January 2013, ST announced full Java support for STM32 F2 and F4-series chips.^[23]
• In February 2013, ST announced STM32 Embedded Coder support for MATLAB and Simulink.^[24]
• In February 2013, ST announced the STM32 F4x9-series chips.^[25]
• In April 2013, ST announced the STM32 F401-series chips.^[26]
• In July 2013, ST announced the STM32 F030-series chips. The STM32 F030-series will also be available in a TSSOP20 package.^[27]
• In September 2013, ST announced the STM32F401C-DISCO and STM32F429I-DISCO boards.^[28]
• In October 2013, ST announced the STM32F0308DISCOVERY board.^[29]
• In December 2013, ST announced that it is joining the mbed project.^[30]

• In January 2014, ST announced the STM32 F0x2-series chips, STM32F072B-DISCO board, and STM32072B-EVAL board.^[31]
• In February 2014, ST announced the STM32 L0-series chips based on the ARM Cortex-M0+ core.^[32]
• In February 2014, ST announced multiple STM32 Nucleo boards with Arduino headers and mbed IDE.^[33]
• In February 2014, ST announced the release of free STM32Cube software tool with graphical configurator and C code generator.^[34]
• In April 2014, ST announced the STM32F30x chips are now available in full production. A new NUCLEO-F302R8 board was also announced.^[35]
• In September 2014, ST announced the STM32 F7 series, the first chips based on the Cortex-M7 core.^[36]

Series

The STM32 family consists of ten series of microcontrollers: F7, F4, F3, F2, F1, F0, L4, L1, L0, W.^[1] Each STM32 microcontroller series is based upon either a Cortex-M4F, Cortex-M3, Cortex-M0+, or Cortex-M0 ARM processor core. The Cortex-M4F is conceptually a Cortex-M3^[4] plus DSP and single-precision floating point instructions.^[3]

STM32 F7

STM32 F7 Series

Produced	From 2014 to Current
Max. CPU clock rate	216  to 216 MHz
Min. feature size	512 KB to 1 MB
Instruction set	Thumb, Thumb-2, Sat Math, DSP, FPU
Microarchitecture	ARM Cortex-M7F

STM32 F4

STM32 F4 Series ^[37]

Produced	From 2011 to Current
Max. CPU clock rate	84  to 180 MHz
Min. feature size	90 nm
Instruction set	Thumb, Thumb-2, Sat Math, DSP, FPU
Microarchitecture	ARM Cortex-M4F [3]

The STM32 F4-series is the first group of STM32 microcontrollers based on the ARM Cortex-M4F core. The F4-series is also the first STM32 series to have DSP and floating point instructions. The F4 is pin-to-pin compatible with the STM32 F2-series and adds higher clock speed, 64K CCM static RAM, full duplex I²S, improved real-time clock, and faster ADCs. The summary for this series is:^{[18][25][26][37][38]}

• Core:
  • ARM Cortex-M4F core at a maximum clock rate of 84 / 168 / 180 MHz.
• Memory:
  • Static RAM consists of up to 192 KB general purpose, 64 KB core coupled memory (CCM), 4 KB battery-backed, 80 bytes battery-backed with tamper-detection erase.
  • Flash consists of 512 / 1024 / 2048 KB general purpose, 30 KB system boot, 512 bytes one-time programmable (OTP), 16 option bytes.
  • Each chip has a factory-programmed 96-bit unique device identifier number.
• Peripherals:
  • Common peripherals included in all IC packages are USB 2.0 OTG HS and FS, two CAN 2.0B, one SPI + two SPI or full-duplex I²S, three I²C, four USART, two UART, SDIO for SD/MMC cards, twelve 16-bit timers, two 32-bit timers, two watchdog timers, temperature sensor, 16 or 24 channels into three ADCs, two DACs, 51 to 140 GPIOs, sixteen DMA, improved real-time clock (RTC), cyclic redundancy check (CRC) engine, random number generator (RNG) engine. Larger IC packages add 8/16-bit external memory bus capabilities.
  • The STM32F4x7 models add ethernet MAC and camera interface.
  • The STM32F41x/43x models add a cryptographic processor for DES / TDES / AES, and a hash processor for SHA-1 and MD5.
  • The STM32F4x9 models add a LCD-TFT controller.
• Oscillators consists of internal (16 MHz, 32 kHz), optional external (4 to 26 MHz, 32.768 to 1000 kHz).
• IC packages: WLCSP64, LQFP64, LQFP100, LQFP144, LQFP176, UFBGA176. STM32F429/439 also offers LQFP208 and UFBGA216.
• Operating voltage range is 1.8 to 3.6 volt.

STM32 F3

STM32 F3 Series ^[39]

Produced	From 2012 to Current
Max. CPU clock rate	72 MHz
Instruction set	Thumb, Thumb-2, Sat Math, DSP, FPU
Microarchitecture	ARM Cortex-M4F [3]

The STM32 F3-series is the second group of STM32 microcontrollers based on the ARM Cortex-M4F core, and the most recent series from ST. The F3 is almost pin-to-pin compatible with the STM32 F1-series. The summary for this series is:^[21][22][39]

• Core:
  • ARM Cortex-M4F core at a maximum clock rate of 72 MHz.
• Memory:
  • Static RAM consists of 16 / 24 / 32 / 40 KB general purpose with hardware parity check, 0 / 8 KB core coupled memory (CCM) with hardware parity check, 64 / 128 bytes battery-backed with tamper-detection erase.
  • Flash consists of 64 / 128 / 256 KB general purpose, 8 KB system boot, and option bytes.
  • Each chip has a factory-programmed 96-bit unique device identifier number.
• Peripherals:
  • Each F3-series includes various peripherals that vary from line to line.
• Oscillators consists of internal (8 MHz, 40 kHz), optional external (1 to 32 MHz, 32.768 to 1000 kHz).
• IC packages: LQFP48, LQFP64, LQFP100, UFBGA100.
• Operating voltage range is 2.0 to 3.6 volt.

The distinguishing feature for this series is presence of four fast, 12-bit, simultaneous sampling ADCs (multiplexer to over 30 channels), and interestingly, four matched, 8 MHz bandwidth OpAmps with all pins exposed and additionally internal PGA (Programmable Gain Array) network. The exposed pads allow for a range of analogue signal conditioning circuits like band-pass filters, anti-alias filters, charge amplifiers, integrators/differentiators, 'instrumentation' high-gain differential inputs, and other. This eliminates need for external OpAmps for many applications. The built-in two-channel DAC has arbitrary waveform as well as a hardware-generated waveform (sine, triangle, noise etc.) capability. All analogue devices can be completely independent, or partially internally connected, meaning that one can have nearly everything that is needed for an advanced measurement and sensor interfacing system in a single chip.

The four ADCs can be simultaneously sampled making a wide range of precision analogue control equipment possible. It is also possible to use a hardware scheduler for the multiplexer array, allowing good timing accuracy when sampling more than 4 channels, independent of the main processor thread. The sampling and multiplexing trigger can be controlled from a variety of sources including timers and built-in comparators, allowing for irregular sampling intervals where needed.

The op-amps inputs feature 2-to-1 analogue multiplexer, allowing for a total of eight analogue channels to be pre-processed using the op-amp; all the op-amp outputs can be internally connected to ADCs.

STM32 F2

STM32 F2 Series ^[40]

Produced	From 2010 to Current
Max. CPU clock rate	120 MHz
Min. feature size	90 nm
Instruction set	Thumb, Thumb-2, Saturated Math
Microarchitecture	ARM Cortex-M3 [4]

The STM32 F2-series of STM32 microcontrollers based on the ARM Cortex-M3 core. It is the most recent and fastest Cortex-M3 series. The F2 is pin-to-pin compatible with the STM32 F4-series. The summary for this series is:^[15][40][41]

• Core:
  • ARM Cortex-M3 core at a maximum clock rate of 120 MHz.
• Memory:
  • Static RAM consists of 64 / 96 / 128 KB general purpose, 4 KB battery-backed, 80 bytes battery-backed with tamper-detection erase.
  • Flash consists of 128 / 256 / 512 / 768 / 1024 KB general purpose, 30 KB system boot, 512 bytes one-time programmable (OTP), 16 option bytes.
  • Each chip has a factory-programmed 96-bit unique device identifier number.
• Peripherals:
  • Common peripherals included in all IC packages are USB 2.0 OTG HS, two CAN 2.0B, one SPI + two SPI or I2S), three I²C, four USART, two UART, SDIO/MMC, twelve 16-bit timers, two 32-bit timers, two watchdog timers, temperature sensor, 16 or 24 channels into three ADCs, two DACs, 51 to 140 GPIOs, sixteen DMA, real-time clock (RTC), cyclic redundancy check (CRC) engine, random number generator (RNG) engine. Larger IC packages add 8/16-bit external memory bus capabilities.
  • The STM32F2x7 models add Ethernet MAC, camera interface, USB 2.0 OTG FS.
  • The STM32F21x models add a cryptographic processor for DES / TDES / AES, and a hash processor for SHA-1 and MD5.
• Oscillators consists of internal (16 MHz, 32 kHz), optional external (4 to 26 MHz, 32.768 to 1000 kHz).
• IC packages: WLCSP64, LQFP64, LQFP100, LQFP144, LQFP176, UFBGA176.
• Operating voltage range is 1.8 to 3.6 volt.

STM32 F1

STM32 F1 Series ^[42]

Produced	From 2007 to Current
Max. CPU clock rate	24  to 72 MHz
Instruction set	Thumb, Thumb-2, Saturated Math
Microarchitecture	ARM Cortex-M3 [4]

The STM32 F1-series was the first group of STM32 microcontrollers based on the ARM Cortex-M3 core and considered their mainstream ARM microcontrollers. The F1-series has evolved over time by increasing CPU speed, size of internal memory, variety of peripherals. There are five F1 lines: Connectivity (STM32F105/107), Performance (STM32F103), USB Access (STM32F102), Access (STM32F101), Value (STM32F100). The summary for this series is:^[42][43][10]

• Core:
  • ARM Cortex-M3 core at a maximum clock rate of 24 / 36 / 48 / 72 MHz.
• Memory:
  • Static RAM consists of 4 / 6 / 8 / 10 / 16 / 20 / 24 / 32 / 48 / 64 / 80 / 96 KB.
  • Flash consists of 16 / 32 / 64 / 128 / 256 / 384 / 512 / 768 / 1024 KB.
• Peripherals:
  • Each F1-series includes various peripherals that vary from line to line.
• IC packages: VFQFPN36, VFQFPN48, LQFP48, WLCSP64, TFBGA64, LQFP64, LQFP100, LFBGA100, LQFP144, LFBGA144.

STM32 F0

STM32 F0 Series ^[44]

Produced	From 2012 to Current
Max. CPU clock rate	48 MHz
Instruction set	Thumb subset, Thumb-2 subset
Microarchitecture	ARM Cortex-M0 [6]

The STM32 F0-series are the first group of ARM Cortex-M0 chips in the STM32 family. The summary for this series is:^{[19][27][31][44]}

• Core:
  • ARM Cortex-M0 core at a maximum clock rate of 48 MHz.
  • Cortex-M0 options include the SysTick Timer.
• Memory:
  • Static RAM consists of 4 / 6 / 8 / 16 / 32 KB general purpose with hardware parity checking.
  • Flash consists of 16 / 32 / 64 / 128 / 256 KB general purpose.
  • Each chip has a factory-programmed 96-bit unique device identifier number.
• Peripherals:
  • Each F0-series includes various peripherals that vary from line to line.
• Oscillators consists of internal (8 MHz, 40 kHz), optional external (1 to 32 MHz, 32.768 to 1000 kHz).
• IC packages: TSSOP20, UFQFPN32, LQFP/UFQFN48, LQFP64, LQFP/UFBGA100.
• Operating voltage range is 2.0 to 3.6 volt with the possibility to go down to 1.65 V.

STM32 L4

STM32 L4 Series

Produced	From 2015 to Current
Max. CPU clock rate	80  to 80 MHz
Instruction set	Thumb, Thumb-2, Sat Math, DSP, FPU
Microarchitecture	ARM Cortex-M4F [3]

STM32 L1

STM32 L1 Series ^[45]

Produced	From 2010 to Current
Max. CPU clock rate	32 MHz
Min. feature size	130 nm
Instruction set	Thumb, Thumb-2, Saturated Math
Microarchitecture	ARM Cortex-M3 [4]

The STM32 L1-series was the first group of STM32 microcontrollers with a primary goal of ultra-low power usage for battery-powered applications. The summary for this series is:^{[13][17][45][46]}

• Core:
  • ARM Cortex-M3 core at a maximum clock rate of 32 MHz.
• Memory:
  • Static RAM consists of 10 / 16 / 32 / 48 / 80 KB general purpose, 80 bytes with tamper-detection erase.
  • Flash consists of 32 / 64 / 128 / 256 / 384 / 512 KB general purpose with ECC, 4 / 8 KB system boot, 32 option bytes, EEPROM consists of 4 / 8 / 12 / 16 KB data storage with ECC.
  • Each chip has a factory-programmed 96-bit unique device identifier number.
• Peripherals:
  • Common peripherals included in all IC packages are USB 2.0 FS, two SPI, two I²C, three USART, eight 16-bit timers, two watchdog timers, temperature sensor, 16 to 24 channels into one ADC, two DACs, 37 to 83 GPIOs, seven DMA, real-time clock (RTC), cyclic redundancy check (CRC) engine. The STM32FL152 line adds a LCD controller.
• Oscillators consists of internal (16 MHz, 38 kHz, variable 64 kHz to 4 MHz), optional external (1 to 26 MHz, 32.768 to 1000 kHz).
• IC packages: UFQFPN48, LQFP48, LQFP64, TFBGA64, LQFP100, UFBGA100.
• Operating voltage range is 1.65 to 3.6 volt.

STM32 L0

STM32 L0 Series ^[47]

Produced	From 2014 to Current
Max. CPU clock rate	32 MHz
Instruction set	Thumb subset, Thumb-2 subset
Microarchitecture	ARM Cortex-M0+ [5]

The STM32 L0-series is the first group of STM32 microcontrollers based on the ARM Cortex-M0+ core. This series targets low power applications. The summary for this series is:^[32][47]

• Core:
  • ARM Cortex-M0+ core at a maximum clock rate of 32 MHz.
  • Debug interface is SWD with breakpoints and watchpoints. JTAG debugging isn't supported.
• Memory:
  • Static RAM sizes of 8 KB general purpose with hardware parity checking, 20 bytes battery-backed with tamper-detection erase.
  • Flash sizes of 32 or 64 KB general purpose (with ECC).
  • EEPROM sizes of 2 KB (with ECC).
  • ROM which contains a boot loader with optional reprogramming of the flash from USART1, USART2, SPI1, SPI2.
  • Each chip has a factory-programmed 96-bit unique device identifier number.
• Peripherals:
  • two USART, one low-power UART, two I²C, two SPI or one I²S, one full-speed USB (only L0x2 and L0x3 chips).
  • one 12-bit ADC with multiplexer, one 12-bit DAC, two analog comparators, temperature sensor.
  • timers, low-power timers, watchdog timers, 5 V-tolerant GPIOs, real-time clock, DMA controller, CRC engine.
  • capacitive touch sense and 32-bit random number generator (only L0x2 and L0x3 chips), LCD controller (only L0x3 chips), 128-bit AES engine (only L06x chips).
• Oscillators consists of optional external 1 to 24 MHz crystal or oscillator, optional external 32.768 kHz crystal or ceramic resonator, multiple internal oscillators, and one PLL.
• IC packages are LQFP48, LQFP64, TFBGA64.
• Operating voltage range is 1.8 to 3.6 volt, including a programmable brownout detector.

STM32 W

STM32 W Series ^[48]

Max. CPU clock rate	24 MHz
Instruction set	Thumb, Thumb-2, Saturated Math
Microarchitecture	ARM Cortex-M3 [4]

The STM32 W-series of ARM chips primary feature is targeting RF communication applications. The summary for this series is:^[48]

• Core:
  • ARM Cortex-M3 core at a maximum clock rate of 24 MHz.
• Memory:
  • Static RAM consists of 8 / 16 kB.
  • Flash consists of 64 / 128 / 192 / 256 kB.
• Peripherals:
  • Each W-series includes various peripherals that vary from line to line.
• IC packages: VFQFPN40, VFQFPN48, UFQFPN48.

STM32 J

STMicroelectronics provides a selection of STM32 microcontrollers ready to be used with Java programming language. This special series embeds the required features to execute Java programs. They are based on the existing STM32 F1, F2, F4, F0, L0 families. There are two sets of special part numbers enabled for Java: Production part numbers end in the letter "J", and sample part numbers end in the letter "U".^[23][49]

Development boards

Arduino boards

The following are Arduino header-compatible boards with STM32 microcontrollers. The Nucleo boards (see next section) also have Arduino headers.

• Maple board by Leaflabs has a STM32F103RB microcontroller. A C/C++ library called libmaple is available to make it easier to migrate from Arduino.
• OLIMEXINO-STM32 board by Olimex has a STM32F103RBT6 microcontroller and similar to the Maple board.

Nucleo boards

Nucleo family of boards by STMicroelectronics with mbed IDE development.^[30][33] The Nucleo board has an onboard ST-LINK/V2-1 host adapter that supports SWD debugging / virtual COM port / mass storage. Each board has Arduino female headers and a new STM32 Morpho connectors consisting of two 19x2 male pin headers. The PCB uses a common layout that supports many STM32 series using a pin-to-pin compatible LQFP64 packages.

• NUCLEO-F446RE board for STM32F446RET6 microcontroller with 180 MHz Cortex-M4F core, 512 KB flash, 128 KB RAM.
• NUCLEO-F411RE board for STM32F411RET6 microcontroller with 100 MHz Cortex-M4F core, 512 KB flash, 128 KB RAM.
• NUCLEO-F410RB board for STM32F410RBT6 microcontroller.
• NUCLEO-F401RE board for STM32F401RET6 microcontroller with 84 MHz Cortex-M4F core, 512 KB flash, 96 KB RAM.
• NUCLEO-F334R8 board for STM32F334R8T6 microcontroller with 72 MHz Cortex-M4F core, 64 KB flash, 16 KB RAM (parity).
• NUCLEO-F303RE board for STM32F303RET6 microcontroller.
• NUCLEO-F302R8 board for STM32F302R8T6 microcontroller with 72 MHz Cortex-M4F core, 64 KB flash, 16 KB RAM.^[35]
• NUCLEO-F103RB board for STM32F103RBT6 microcontroller with 72 MHz Cortex-M3 core, 128 KB flash, 20 KB RAM.
• NUCLEO-F091RC board for STM32F091RCT6 microcontroller.
• NUCLEO-F072RB board for STM32F072RBT6 microcontroller with 48 MHz Cortex-M0 core, 128 KB flash, 16 KB RAM (parity).
• NUCLEO-F070RB board for STM32F070RBT6 microcontroller with 48 MHz Cortex-M0 core, 128 KB flash, 16 KB RAM (parity).
• NUCLEO-F030R8 board for STM32F030R8T6 microcontroller with 48 MHz Cortex-M0 core, 64 KB flash, 8 KB RAM (parity).

Low power

• NUCLEO-L476RG board for STM32L476RGT6 microcontroller with 80 MHz Cortex-M4F core, 1 MB flash, 128 KB RAM (parity).
• NUCLEO-L152RE board for STM32L152RET6 microcontroller with 32 MHz Cortex-M3 core, 512 KB flash (ECC), 80 KB RAM, 16 KB EEPROM (ECC).
• NUCLEO-L073RZ board for STM32L073RZT6 microcontroller.
• NUCLEO-L053R8 board for STM32L053R8T6 microcontroller with 32 MHz Cortex-M0+ core, 64 KB flash (ECC), 8 KB RAM, 2 KB EEPROM (ECC).

Discovery boards

The following Discovery evaluation boards are sold by STMicroelectronics to provide a quick and easy way for engineers to evaluate their microcontroller chips. These kits are available from various distributors for less than US$20. The STMicroelectronics evaluation product licence agreement forbids their use in any production system or any product that is offered for sale.^[50]

Each board includes an on-board ST-LINK for programming and debugging via a Mini-B USB connector. The power for each board is provided by a choice of the 5 V via the USB cable, or an external 5 V power supply. They can be used as output power supplies of 3 V or 5 V (current must be less than 100 mA). All Discovery boards also include a voltage regulator, reset button, user button, multiple LEDs, SWD header on top of each board, and rows of header pins on the bottom.^[51]

An open-source project was created to allow Linux to communicate with the ST-LINK debugger.^[52]

ChibiOS/RT, a free RTOS, has been ported to run on some of the Discovery boards.^[53][54][55]

STM32L476GDISCOVERY

• A discovery board for STM32L476VGT6 microcontroller with 80 MHz ARM Cortex-M4F core, 1024 KB flash, 128 KB RAM in LQFP100 package

STM32F429IDISCOVERY

• A discovery board for STM32F429ZIT6 microcontroller with 180 MHz ARM Cortex-M4F core, 2048 KB flash, 256 KB RAM, 4 KB battery-backed RAM in LQFP144 package.^[28]
• This board includes an integrated ST-LINK/V2 debugger via Mini-B USB connector, 8 MB SDRAM (IS42S16400J), 2.4-inch 320x200 TFT LCD color display (SF-TC240T), touchscreen controller (STMPE811), gyroscope (L3GD20), 2 user LEDs, user button, reset button, Full-Speed USB OTG to second Micro-AB USB connector, and two 32x2 male pin headers.

STM32F4DISCOVERY

• A discovery board for STM32F407VGT6 microcontroller with 168 MHz ARM Cortex-M4F core, 1024 KB flash, 192 KB RAM, 4 KB battery-backed RAM in LQFP100 package.^[18]
• This board includes an integrated ST-LINK/V2 debugger via Mini-B USB connector, accelerometer (LIS302DL), microphone (MP45DT02), audio codec (CS43L22), 3.5 mm audio jack, 4 user LEDs, user button, reset button, Full-Speed USB OTG to second Micro-AB USB connector, and two 25x2 male pin headers.
• A separate STM32F4DIS-BB baseboard is available.

STM32F401CDISCOVERY

• A discovery board for STM32F401VCT6 microcontroller with 84 MHz ARM Cortex-M4F core, 256 KB flash, 64 KB RAM in LQFP100 package.^[28]
• This board includes an integrated ST-LINK/V2 debugger via Mini-B USB connector, accelerometer/compass (LSM303DLHC), gyroscope (L3GD20), microphone (MP45DT02), audio codec (CS43L22), 3.5 mm audio jack, 4 user LEDs, user button, reset button, Full-Speed USB OTG to second Micro-AB USB connector, and two 25x2 male pin headers.

STM32F3DISCOVERY

• A discovery board for STM32F303VCT6 microcontroller with 72 MHz ARM Cortex-M4F core, 256 KB flash, 48 KB RAM (24K with parity) in LQFP100 package.^[22]
• This board includes an integrated ST-LINK/V2 debugger via Mini-B USB connector, accelerometer/compass (LSM303DLHC), gyroscope (L3GD20), 8 user LEDs, user button, reset button, Full-Speed USB to second Mini-B USB connector, and two 25x2 male pin headers.

STM32VLDISCOVERY

• A discovery board for STM32F100RBT6 microcontroller with 24 MHz ARM Cortex-M3 core, 128 KB flash, 8 KB RAM in LQFP64 package.^[14][16]
• This board includes an integrated ST-LINK debugger via Mini-B USB connector, 2 user LEDs, user button, reset button, and two 28x1 male pin headers.

STM32L-DISCOVERY

• A discovery board for STM32L152RBT6 microcontroller with 32 MHz ARM Cortex-M3 core, 128 KB flash (with ECC), 16 KB RAM, 4 KB EEPROM (with ECC) in LQFP64 package.^[16]
• This board includes an integrated ST-LINK/V2 debugger via Mini-B USB connector, 24-segment LCD, touch sensors, 2 user LEDs, user button, reset button, and two 28x1 male pin headers.
• This board is currently End-Of-Life and replaced by the 32L152CDISCOVERY board.

STM32L152CDISCOVERY

• A discovery board for STM32L152RCT6 microcontroller with 32 MHz ARM Cortex-M3 core, 256 KB flash (with ECC), 32 KB RAM, 8 KB EEPROM (with ECC) in LQFP64 package.
• This board includes an integrated ST-LINK/V2 debugger via Mini-B USB connector, 24-segment LCD, touch sensors, 2 user LEDs, user button, reset button, and two 28x1 male pin headers.

STM32L100CDISCOVERY

• A discovery board for STM32L100RCT6 microcontroller with 32 MHz ARM Cortex-M3 core, 256 KB flash (with ECC), 16 KB RAM, 4 KB EEPROM (with ECC) in LQFP64 package.
• This board includes an integrated ST-LINK/V2 debugger via Mini-B USB connector, 2 user LEDs, user button, reset button, and two 33x1 male pin headers.

STM32F072BDISCOVERY

• A discovery board for STM32F072RBT6 microcontroller with 48 MHz ARM Cortex-M0 core, 128 KB flash, 16 KB RAM (with parity) in LQFP64 package.^[31]
• This board includes an integrated ST-LINK/V2 debugger via Mini-B USB connector, gyroscope (L3GD20), 4 user LEDs, user button, reset button, linear touch keys, Full-Speed USB to second Mini-B USB connector, and two 33x1 male pin headers.

STM32F0DISCOVERY

• A discovery board for STM32F051R8T6 microcontroller with 48 MHz ARM Cortex-M0 core, 64 KB flash, 8 KB RAM (with parity) in LQFP64 package.^[20]
• This board includes an integrated ST-LINK/V2 debugger via Mini-B USB connector, 2 user LEDs, user button, reset button, and two 33x1 male pin headers.
• A prototyping perfboard with 0.1-inch (2.54 mm) grid of holes is included.

STM32F0308DISCOVERY

• A discovery board for STM32F030R8T6 microcontroller with 48 MHz ARM Cortex-M0 core, 64 KB flash, 8 KB RAM (with parity) in LQFP64 package.^[29]
• This board includes an integrated ST-LINK/V2 debugger via Mini-B USB connector, 2 user LEDs, user button, reset button, and two 33x1 male pin headers.
• A prototyping perfboard with 0.1-inch (2.54 mm) grid of holes is included.

Evaluation boards

The following evalulation kits are sold by STMicroelectronics.^[56]

STM32W-RFCKIT

• An RF evaluation board for STM32 W-series.
• It contains two boards, each with a STM32W108 SoC microcontroller in VFQFPN40 and VFQFPN48 packages.
• The evaluation board has a built-in 2.4 GHz IEEE 802.15.4 transceiver and Lower MAC (so supports 802.15.4, ZigBee RF4CE, ZigBee Pro, 6LoWPAN (Contiki) wireless protocols). The SoC contains 128-Kbyte flash and 8-Kbyte RAM memory. Flash memory is upgradable too via USB. It has an ARM Serial Wire Debug (SWD) interface (Remote board) and is designed to be powered by USB or with 2 AAA batteries (Remote board). There are two user-defined LEDs (green and yellow) and five push buttons to create easy-to-use remote functions (Remote board).

STM3220G-JAVA

A ready-to-use Java development kits for its STM32 microcontrollers. The STM3220G-JAVA Starter Kit combines an evaluation version of IS2T's MicroEJ® Software Development Kit (SDK) and the STM32F2 series microcontroller evaluation board providing everything engineers need to start their projects. MicroEJ provides extended features to create, simulate, test and deploy Java applications in embedded systems. Support for Graphical User Interface (GUI) development includes a widget library, design tools including storyboarding, and tools for customizing fonts.^[57] STM32 microcontrollers that embed Java have a Part Number that ends with J like STM32F205VGT6J.

Partner boards

The following evalulation kits are sold by partners of STMicroelectronics and listed on the ST website.

STM32-PerformanceStick

• An evaluation board for STM32 F1-series.^[58]
• It contains a STM32F103RBT6 microcontroller at 72 MHz with 128 KB flash and 20 KB RAM in LQFP64 package.
• This board also includes in-circuit debugger via USB, 3 V battery, LEDs, edge card connector.
• The price is approximately US$65.

EvoPrimers for STM32

• A prototyping environment for a variety of STM32 variants, which allows users to create their applications using an application programming interface (API) to implement device peripherals and a range of evaluation features on the EvoPrimer base including TFT color touchscreen, graphical user interface, joy stick, codec-based audio, SD card, IrDA and standard peripherals such as USB, USART, SPI, I2C, CAN, etc.
• EvoPrimer target boards are available for several variants including STM32F103, STM32F107, STM32L152 and STM32F407.
• The EvoPrimer base includes a device programming and application debugging interface and comes with a Raisonance software tool set for coding, compiling and debugging the user's application.
• The CircleOS utility allows the user to code their applications relying on an application programming interface, making it possible to program the application without having to master the configuration of device peripherals.
• The price is US$100 to $120.

Development tools

Cortex-M

STM32

Design utilities

• STM32CubeMX, by STMicroelectronics, a freeware package for Windows that is a graphical software configuration tool that allows generating C initialization code using graphical wizards. The package was first release in February 2014 with graphical peripheral allocation support for every STM32 chip. As of January 2015, the tool supports all STM32 series. It can generate source code usable directly on the most current ARM Cortex-M IDEs, including the free System Workbench for STM32 IDE. STM32CubeMX is likely an evolution of the former MicroXplorer tool, because the saved "IOC" configuration file from STM32CubeMX shows the word "MicroXplorer" in it. A 32-bit Java Runtime Environment (JRE) must be installed prior to running STM32CubeMX.^[59]

Debug utilities

• STM-STUDIO, by STMicroelectronics, a freeware package for Windows to help debug and diagnose STM32 applications while they are running by reading and displaying their variables in real-time. STM-STUDIO connects to any STM32 using any ST-LINK type of device via JTAG or SWD debug bus protocols. It can log captured data to a file and replay later. It parses debugging information from the ELF application executable file. A 32-bit Java Runtime Environment (JRE) must be installed prior to running STM-STUDIO. The STM32 ST-LINK Utility must be installed prior to running STM-STUDIO.^[59]
• System Workbench for STM32, by Ac6, a freeware IDE running on Windows, Linux and MacOS/X to develop, debug and diagnose STM32 applications. System Workbench for STM32 can be used to develop on any STM32 using any ST-LINK/V2 type of device via JTAG or SWD debug bus protocols. It is based on Eclipse and the GNU GCC toolchain and supports out-of-the-box all ST-provided evaluation boards (Eval, Discovery or Nucleo). A 32-bit Java Runtime Environment (JRE^[59]) will automatically be installed if needed as well as the STM32 ST-LINK driver.
• VisualGDB, by Sysprogs, a debug plugin for Microsoft Visual Studio that allows developing and debugging STM32 applications.
• EPS Debugger, by Comsytec, a debug plugin for Code::Blocks that includes compiler, debugger, project wizard for STM32.

Flash programming via USB

• STM32 ST-LINK Utility, by STMicroelectronics, a freeware package for Windows to perform in-system programming of STM32 microcontrollers using the USB-based ST-LINK/V2 interface device via JTAG or SWD debug bus protocols. This software can upgrade the firmware in the ST-LINK device, which includes the embedded ST-LINK on all of the STM32 DISCOVERY boards.^[60] During installation of this utility, a USB driver is installed to provide a communication interface with the ST-LINK device, which in turn also allows various IDEs to use the ST-LINK for debugging.
• ST Visual Programmer (STVP), by STMicroelectronics, a freeware package for Windows to perform in-system programming of the flash in STM32 microcontrollers using a USB-based ST-LINK device.
• DfuSe, by STMicroelectronics, a freeware package for Windows to load DFU programs into the flash of USB-based STM32 microcontrollers.
• qstlink2, an open source multi-platform ST-LINK/V2 client, based on QT.
• texane stlink, an opensource ST-LINK/V2 client for linux
• pystlink, an opensource ST-LINK/V2 programmer and debug tool with simple command-line interface for Linux, Mac OS/X and Windows written in python3

Flash programming via USART

All STM32 microcontrollers have a ROM'ed bootloader that supports loading a binary image into its flash memory using one or more peripherals (varies by STM32 family). Since all STM32 bootloaders support loading from the USART peripheral and most boards connect the USART to RS-232 or a USB-to-UART adapter IC, thus it's a universal method to program the STM32 microcontroller. This method requires the target to have a way to enable/disable booting from the ROM'ed bootloader (i.e. jumper / switch / button).

• stm32flash, an open source program for Windows and Linux to perform in-system programming of the STM32 flash via its USART.
• stm32loader, an open source multi-platform Python script to perform in-system programming of the STM32 flash via its USART. Python and Python Serial Port Extension must be installed prior to running stm32loader.

STM32 Java software libraries

• Standard Eclipse Java IDE STM32Java

STM32 C/C++ software libraries

• Standard peripheral library.
• USB device library.
• DSP library.
• Encryption library.
• Motor control library.
• MP3 / WMA / Speex codecs and audio engine.
• Self-test routines.

Documentation

The amount of documentation for all ARM chips is daunting, especially for newcomers. The documentation for microcontrollers from past decades would easily be inclusive in a single document, but as chips have evolved so has the documentation grown. The total documentation is especially hard to grasp for all ARM chips since it consists of documents from the IC manufacturer (STMicroelectronics) and documents from CPU core vendor (ARM Holdings).

A typical top-down documentation tree is: manufacturer website, manufacturer marketing slides, manufacturer datasheet for the exact physical chip, manufacturer detailed reference manual that describes common peripherals and aspects of a physical chip family, ARM core generic user guide, ARM core technical reference manual, ARM architecture reference manual that describes the instruction set(s).

STM32 documentation tree (top to bottom)

1. STM32 website.
2. STM32 marketing slides.
3. STM32 datasheet.
4. STM32 reference manual.
5. ARM core website.
6. ARM core generic user guide.
7. ARM core technical reference manual.
8. ARM architecture reference manual.

STMicroelectronics has additional documents, such as: evaluation board user manuals, application notes, getting started guides, software library documents, errata, and more. See External Links section for links to official STM32 and ARM documents.

Part number decoding

STM32F051R8
STM32xxwwyz

• xx – Family
• ww – subtype: differs in equipment of peripherals and this depend on certain family
• y – Package pin count
• z – FLASH memory size

Family: [xx]^[1][61]

Code	Core	Max freq [MHz]	Max FLASH [KB]	Max SRAM [KB]	target
F0	CortexM0	48	256	32	Mainstream
F1	CortexM3	72	1024	96	Mainstream
F2	CortexM3	120	1024	128	High performance
F3	CortexM4	72	512	80	Mainstream
F4	CortexM4	180	2048	384	High performance
F7	CortexM7	216	1024	320	High performance
L0	CortexM0+	32	192	20	Ultra low-power
L1	CortexM3	32	512	80	Ultra low-power
L4	CortexM4	80	1024	128	Ultra low-power

Package pin count [y] Code Number of pins A 169 B 208 C 48 F 20 G 28 H 40 I 176 J 72 K 32 M 81 N 216 Q 132 R 64 T 36 U 63 V 100 Z 144

FLASH memory size [z] Code FLASH size [KB] 4 16 6 32 8 64 B 128 Z 192 C 256 D 384 E 512 F 768 G 1024 I 2048

See also

• ARM architecture, List of ARM microprocessor cores, ARM Cortex-M
• Microcontroller, List of common microcontrollers
• Embedded system, Single-board microcontroller
• Interrupt, Interrupt handler, Comparison of real-time operating systems
• JTAG, SWD

References

Further reading

• The Insider's Guide To The STM32 ARM Based Microcontroller; 2nd Edition (v1.8); Trevor Martin; Hitex; 96 pages; 2009; ISBN 0-9549988-8-X. (Download) (Other Guides)
• µC/OS-III: The Real-Time Kernel for the STMicroelecronics STM32F107; 1st Edition; Jean Labrosse; Micrium; 820 pages; 2009; ISBN 978-0-9823375-3-0.
• µC/TCP-IP: The Embedded Protocol Stack for the STMicroelectronics STM32F107; 1st Edition; Christian Légaré; Micrium; 824 pages; 2010; ISBN 978-0-9823375-0-9.

External links

Wikimedia Commons has media related to STM32.

STM32 Official Documents

• STM32 official website

STM32 Series	STM32 Website	STM32 Slides	STM32 Reference	ARM CPU Core
F7	Link	n/a	n/a	Cortex-M4F
F4	Link	Slides	F4x5/7/9, F401	Cortex-M4F
F3	Link	n/a	F37x / F38x, F30x / F31x	Cortex-M4F
F2	Link	Slides	F20x / F21x	Cortex-M3
F1	Link	Slides	F101/2/3/5/7 F100	Cortex-M3
F0	Link	n/a	F0x1/2/8, F030	Cortex-M0
L4	Link	.	.	Cortex-M4F
L1	Link	Slides	L1xx	Cortex-M3
L0	Link	n/a	L0xx	Cortex-M0+
W	Link	n/a	n/a	Cortex-M3

ARM Official Documents

Other

• STM32 Communities: Primer
• STM32 USART bus: Article 1, Article 2, Article 3
• STM32 SPI bus: Article 1
• STM32 ADC: Article 1
• STM32 Bit Band Memory: Article 1
• Libraries: ARM CMSIS, libopencm3

Embedded ARM-based chips ARM Holdings ARM architecture List of ARM cores ARM Cortex-A ARM Cortex-R ARM Cortex-M List of ARM Cortex-M development tools Embedded Microcontrollers Cortex-M0 Cypress PSoC 4 Infineon XMC1000 Nordic nRF51 NXP LPC11xx, LPC12xx nuvoTon NuMicro Sonix SN32F700 STMicroelectronics STM32 F0 Toshiba TX00 Cortex-M0+ Atmel SAMD, SAMR Freescale Kinetis E, EA, L, M, V1, W0 Holtek HT32F52xxx NXP LPC8xx, LPC11E6x, LPC11U6x Silicon Labs/Energy Micro EFM32 Zero Spansion FM0+ STMicroelectronics STM32 L0 Cortex-M1 Actel FPGAs Altera FPGAs Xilinx FPGAs Cortex-M3 Actel SmartFusion, SmartFusion 2 Analog Devices ADuCM3xx Atmel SAM3A, SAM3N, SAM3S, SAM3U, SAM3X Cypress Semiconductor PSoC 5 Energy Micro EFM32 Tiny, Gecko, Leopard, Giant Fujitsu FM3 Holtek HT32F NXP LPC13xx, LPC17xx, LPC18xx ON Semiconductor Q32M210 Silicon Labs Precision32 STMicroelectronics STM32 F1, F2, L1, W Texas Instruments F28, LM3, TMS470, OMAP 4 Toshiba TX03 XMOS XS1-XA Cortex-M4 Atmel SAM4L, SAM4N, SAM4S Freescale Kinetis K, W2 Cortex-M4F Atmel SAM4C, SAM4E, SAMG Energy Micro EFM32 Wonder Freescale Kinetis K, V3, V4 Infineon XMC4000 NXP LPC40xx, LPC43xx Spansion FM4 STMicroelectronics STM32 F3, F4 Texas Instruments LM4F/TM4C Cortex-M7 Atmel SAME70, SAMS70, SAMV70 STMicroelectronics STM32 F7 Real-Time Microcontrollers Cortex-R4F Texas Instruments RM4, TMS570 Cortex-R5F Scaleo OLEA Texas Instruments RM57 Xilinx ZynqMP Cortex-R7F n/a

Microcontrollers Main Single-board microcontroller Special function register Architectures 8051 ARM AVR PIC C166 TriCore FR-V 6800 Families 4-bit TLCS-47 8-bit AVR PIC10/12/16/17/18 COP8 MCS-48 MCS-51 Z8 eZ80 HC08 HC11 H8 TLCS-870 XC800 16-bit C166 CR16/CR16C H8S MSP430 PIC24/dsPIC R8C TLCS-900 XC 2000 XE166 32-bit Am29000 ARM families AVR32 ColdFire CRX FR FR-V H8SX MPC5xx PIC32 PowerPC TLCS-900 TriCore V850 Interfaces Programming In-circuit serial programming (ICSP) In-system programming (ISP) Program and Debug Interface (PDI) High-voltage serial programming (HVSP) High voltage parallel programming (HVPP) Bootloader ROM aWire Debugging debugWIRE Joint Test Action Group (JTAG) In-circuit debugging (ICD) In-circuit emulator (ICE) In-target probe (ITP) Simulators gpsim Lists Common microcontrollers By manufacturer Freescale Intel See also Embedded system Programmable logic controller