STM32L451REI6

STM32L451xx Ultra-low-power Arm® Cortex®-M4 32-bit MCU+FPU, 100DMIPS, up to 512KB Flash, 160KB SRAM, analog, audio Datasheet - production data Features • Ultra-low-power with FlexPowerControl – 1.71 V to 3.6 V power supply – -40 °C to 85/125 °C temperature range – 145 nA in VBAT mode: supply for RTC and 32x32-bit backup registers – 22 nA Shutdown mode (5 wakeup pins) – 106 nA Standby mode (5 wakeup pins) – 375 nA Standby mode with RTC – 2.05 µA Stop 2 mode, 2.40 µA with RTC – 84 µA/MHz run mode – Batch acquisition mode (BAM) – 4 µs wakeup from Stop mode – Brown out reset (BOR) – Interconnect matrix • Core: Arm® 32-bit Cortex®-M4 CPU with FPU, Adaptive real-time accelerator (ART Accelerator™) allowing 0-wait-state execution from Flash memory, frequency up to 80 MHz, MPU, 100DMIPS and DSP instructions • Performance benchmark – 1.25 DMIPS/MHz (Drystone 2.1) – 273.55 CoreMark® (3.42 CoreMark/MHz @ 80 MHz) • Energy benchmark – 335 ULPMark™ CP score – 104 ULPMark™ PP score • Clock Sources – 4 to 48 MHz crystal oscillator – 32 kHz crystal oscillator for RTC (LSE) – Internal 16 MHz factory-trimmed RC (±1%) – Internal low-power 32 kHz RC (±5%) – Internal multispeed 100 kHz to 48 MHz oscillator, auto-trimmed by LSE (better than ±0.25 % accuracy) – Internal 48 MHz with clock recovery – 2 PLLs for system clock, audio, ADC October 2020 This is information on a product in full production. LQFP100 (14×14) UFBGA100 (7×7) WLCSP64 UFQFPN48 (7×7) LQFP64 (10×10) UFBGA64 (5×5) (3.36×3.66) LQFP48 (7×7) • Up to 83 fast I/Os, most 5 V-tolerant • RTC with HW calendar, alarms and calibration • Up to 21 capacitive sensing channels: support touchkey, linear and rotary touch sensors • 12x timers: 1x 16-bit advanced motor-control, 1x 32-bit and 3x 16-bit general purpose, 2x 16bit basic, 2x low-power 16-bit timers (available in Stop mode), 2x watchdogs, SysTick timer • Memories – Up to 512 KB single bank Flash, proprietary code readout protection – 160 KB of SRAM including 32 KB with hardware parity check – Quad SPI memory interface • Rich analog peripherals (independent supply) – 1x 12-bit ADC 5 Msps, up to 16-bit with hardware oversampling, 200 µA/Msps – 1x 12-bit DAC output channels, low-power sample and hold – 1x operational amplifier with built-in PGA – 2x ultra-low-power comparators – Accurate 2.5 V or 2.048 V reference voltage buffered output • 16x communication interfaces – 1x SAI (serial audio interface) – 4x I2C FM+(1 Mbit/s), SMBus/PMBus – 3x USARTs (ISO 7816, LIN, IrDA, modem) – 1x UART (LIN, IrDA, modem) – 1x LPUART (Stop 2 wake-up) – 3x SPIs (and 1x Quad SPI) – CAN (2.0B Active) and SDMMC interface – IRTIM (Infrared interface) • 14-channel DMA controller DS11910 Rev 5 1/207 www.st.com STM32L451xx • True random number generator • CRC calculation unit, 96-bit unique ID • Development support: serial wire debug (SWD), JTAG, Embedded Trace Macrocell™ • All packages are ECOPACK2® compliant Table 1. Device summary Reference STM32L451xx 2/207 Part numbers STM32L451CC, STM32L451RC, STM32L451VC, STM32L451CE, STM32L451RE, STM32L451VE DS11910 Rev 5 STM32L451xx Contents Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3 Functional overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.1 Arm® Cortex®-M4 core with FPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.2 Adaptive real-time memory accelerator (ART Accelerator™) . . . . . . . . . 17 3.3 Memory protection unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.4 Embedded Flash memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.5 Embedded SRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.6 Firewall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.7 Boot modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.8 Cyclic redundancy check calculation unit (CRC) . . . . . . . . . . . . . . . . . . . 20 3.9 Power supply management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.9.1 Power supply schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.9.2 Power supply supervisor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.9.3 Voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.9.4 Low-power modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.9.5 Reset mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3.9.6 VBAT operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3.10 Interconnect matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 3.11 Clocks and startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 3.12 General-purpose inputs/outputs (GPIOs) . . . . . . . . . . . . . . . . . . . . . . . . . 37 3.13 Direct memory access controller (DMA) . . . . . . . . . . . . . . . . . . . . . . . . . . 37 3.14 Interrupts and events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 3.15 3.16 3.14.1 Nested vectored interrupt controller (NVIC) . . . . . . . . . . . . . . . . . . . . . . 38 3.14.2 Extended interrupt/event controller (EXTI) . . . . . . . . . . . . . . . . . . . . . . 38 Analog to digital converter (ADC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 3.15.1 Temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 3.15.2 Internal voltage reference (VREFINT) . . . . . . . . . . . . . . . . . . . . . . . . . . 40 3.15.3 VBAT battery voltage monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Digital to analog converter (DAC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 DS11910 Rev 5 3/207 6 Contents STM32L451xx 3.17 Voltage reference buffer (VREFBUF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 3.18 Comparators (COMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 3.19 Operational amplifier (OPAMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 3.20 Touch sensing controller (TSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 3.21 Digital filter for Sigma-Delta modulators (DFSDM) . . . . . . . . . . . . . . . . . . 43 3.22 Random number generator (RNG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 3.23 Timers and watchdogs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 3.23.1 Advanced-control timer (TIM1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 3.23.2 General-purpose timers (TIM2, TIM3, TIM15, TIM16) . . . . . . . . . . . . . . 46 3.23.3 Basic timer (TIM6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 3.23.4 Low-power timer (LPTIM1 and LPTIM2) . . . . . . . . . . . . . . . . . . . . . . . . 47 3.23.5 Infrared interface (IRTIM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 3.23.6 Independent watchdog (IWDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 3.23.7 System window watchdog (WWDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 3.23.8 SysTick timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 3.24 Real-time clock (RTC) and backup registers . . . . . . . . . . . . . . . . . . . . . . 48 3.25 Inter-integrated circuit interface (I2C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 3.26 Universal synchronous/asynchronous receiver transmitter (USART) . . . 50 3.27 Low-power universal asynchronous receiver transmitter (LPUART) . . . . 51 3.28 Serial peripheral interface (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 3.29 Serial audio interfaces (SAI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 3.30 Controller area network (CAN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.31 Secure digital input/output and MultiMediaCards Interface (SDMMC) . . . 53 3.32 Clock recovery system (CRS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 3.33 Quad SPI memory interface (QUADSPI) . . . . . . . . . . . . . . . . . . . . . . . . . 54 3.34 Development support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 3.34.1 Serial wire JTAG debug port (SWJ-DP) . . . . . . . . . . . . . . . . . . . . . . . . . 56 3.34.2 Embedded Trace Macrocell™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 4 Pinouts and pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 5 Memory mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 6 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 6.1 4/207 Parameter conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 DS11910 Rev 5 STM32L451xx Contents 6.1.1 Minimum and maximum values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 6.1.2 Typical values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 6.1.3 Typical curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 6.1.4 Loading capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 6.1.5 Pin input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 6.1.6 Power supply scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 6.1.7 Current consumption measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 6.2 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 6.3 Operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 6.3.1 General operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 6.3.2 Operating conditions at power-up / power-down . . . . . . . . . . . . . . . . . . 92 6.3.3 Embedded reset and power control block characteristics . . . . . . . . . . . 92 6.3.4 Embedded voltage reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 6.3.5 Supply current characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 6.3.6 Wakeup time from low-power modes and voltage scaling transition times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 6.3.7 External clock source characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 117 6.3.8 Internal clock source characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 122 6.3.9 PLL characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 6.3.10 Flash memory characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 6.3.11 EMC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 6.3.12 Electrical sensitivity characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 6.3.13 I/O current injection characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 6.3.14 I/O port characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 6.3.15 NRST pin characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 6.3.16 Extended interrupt and event controller input (EXTI) characteristics . . 140 6.3.17 Analog switches booster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 6.3.18 Analog-to-Digital converter characteristics . . . . . . . . . . . . . . . . . . . . . 141 6.3.19 Digital-to-Analog converter characteristics . . . . . . . . . . . . . . . . . . . . . 154 6.3.20 Voltage reference buffer characteristics . . . . . . . . . . . . . . . . . . . . . . . 159 6.3.21 Comparator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 6.3.22 Operational amplifiers characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 162 6.3.23 Temperature sensor characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 6.3.24 VBAT monitoring characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 6.3.25 Timer characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 6.3.26 Communication interfaces characteristics . . . . . . . . . . . . . . . . . . . . . . 167 DS11910 Rev 5 5/207 6 Contents 7 STM32L451xx Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 7.1 LQFP100 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 7.2 UFBGA100 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 7.3 LQFP64 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 7.4 UFBGA64 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 7.5 WLCSP64 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 7.6 LQFP48 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195 7.7 UFQFPN48 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 7.8 Thermal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 7.8.1 Reference document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 7.8.2 Selecting the product temperature range . . . . . . . . . . . . . . . . . . . . . . 201 8 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 6/207 DS11910 Rev 5 STM32L451xx List of tables List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Table 13. Table 14. Table 15. Table 16. Table 17. Table 18. Table 19. Table 20. Table 21. Table 22. Table 23. Table 24. Table 25. Table 26. Table 27. Table 28. Table 29. Table 30. Table 31. Table 32. Table 33. Table 34. Table 35. Table 36. Table 37. Table 38. Table 39. Table 40. Table 41. Table 42. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 STM32L451xx family device features and peripheral counts . . . . . . . . . . . . . . . . . . . . . . . 14 Access status versus readout protection level and execution modes. . . . . . . . . . . . . . . . . 18 STM32L451xx modes overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Functionalities depending on the working mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 STM32L451xx peripherals interconnect matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 DMA implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Temperature sensor calibration values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Internal voltage reference calibration values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 DFSDM1 implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Timer feature comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 I2C implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 STM32L451xx USART/UART/LPUART features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 SAI implementation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Legend/abbreviations used in the pinout table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 STM32L451xx pin definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Alternate function AF0 to AF7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Alternate function AF8 to AF15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 STM32L451xx memory map and peripheral register boundary addresses . . . . . . . . . . . . 84 Voltage characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Current characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Thermal characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 General operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Operating conditions at power-up / power-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Embedded reset and power control block characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . 92 Embedded internal voltage reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Current consumption in Run and Low-power run modes, code with data processing running from Flash, ART enable (Cache ON Prefetch OFF) . . . . . . . . . . . . . . . . . . . . . . . 98 Current consumption in Run and Low-power run modes, code with data processing running from Flash, ART disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Current consumption in Run and Low-power run modes, code with data processing running from SRAM1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Typical current consumption in Run and Low-power run modes, with different codes running from Flash, ART enable (Cache ON Prefetch OFF) . . . . . . . . . . . . . . . . . . . . . . 101 Typical current consumption in Run and Low-power run modes, with different codes running from Flash, ART disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Typical current consumption in Run and Low-power run modes, with different codes running from SRAM1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Current consumption in Sleep and Low-power sleep modes, Flash ON . . . . . . . . . . . . . 103 Current consumption in Low-power sleep modes, Flash in power-down . . . . . . . . . . . . . 104 Current consumption in Stop 2 mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Current consumption in Stop 1 mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Current consumption in Stop 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Current consumption in Standby mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Current consumption in Shutdown mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Current consumption in VBAT mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 Peripheral current consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 Low-power mode wakeup timings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 DS11910 Rev 5 7/207 9 List of tables Table 43. Table 44. Table 45. Table 46. Table 47. Table 48. Table 49. Table 50. Table 51. Table 52. Table 53. Table 54. Table 55. Table 56. Table 57. Table 58. Table 59. Table 60. Table 61. Table 62. Table 63. Table 64. Table 65. Table 66. Table 67. Table 68. Table 69. Table 70. Table 71. Table 72. Table 73. Table 74. Table 75. Table 76. Table 77. Table 78. Table 79. Table 80. Table 81. Table 82. Table 83. Table 84. Table 85. Table 86. Table 87. Table 88. Table 89. Table 90. Table 91. Table 92. Table 93. Table 94. 8/207 STM32L451xx Regulator modes transition times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Wakeup time using USART/LPUART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 High-speed external user clock characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Low-speed external user clock characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 HSE oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 LSE oscillator characteristics (fLSE = 32.768 kHz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 HSI16 oscillator characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 MSI oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 HSI48 oscillator characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 LSI oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 PLL, PLLSAI1 characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 Flash memory characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 Flash memory endurance and data retention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 EMS characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 EMI characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 ESD absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 Electrical sensitivities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 I/O current injection susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 I/O static characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Output voltage characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 I/O AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 NRST pin characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 EXTI Input Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 Analog switches booster characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 ADC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Maximum ADC RAIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 ADC accuracy - limited test conditions 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 ADC accuracy - limited test conditions 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 ADC accuracy - limited test conditions 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 ADC accuracy - limited test conditions 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 DAC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 DAC accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 VREFBUF characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 COMP characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 OPAMP characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 TS characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 VBAT monitoring characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 VBAT charging characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 TIMx characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 IWDG min/max timeout period at 32 kHz (LSI). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 WWDG min/max timeout value at 80 MHz (PCLK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 I2C analog filter characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 SPI characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Quad SPI characteristics in SDR mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 QUADSPI characteristics in DDR mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 SAI characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 SD / MMC dynamic characteristics, VDD=2.7 V to 3.6 V . . . . . . . . . . . . . . . . . . . . . . . . . 177 eMMC dynamic characteristics, VDD = 1.71 V to 1.9 V . . . . . . . . . . . . . . . . . . . . . . . . . . 178 LQFP100 - Mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 UFBGA100 - Mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 UFBGA100 - Recommended PCB design rules (0.5 mm pitch BGA). . . . . . . . . . . . . . . . 184 LQFP64 - Mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 DS11910 Rev 5 STM32L451xx Table 95. Table 96. Table 97. Table 98. Table 99. Table 100. Table 101. Table 102. Table 103. List of tables UFBGA64 - Mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 UFBGA64 - Recommended PCB design rules (0.5 mm pitch BGA). . . . . . . . . . . . . . . . . 190 WLCSP64 - Mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 WLCSP64 - Recommended PCB design rules (0.4 mm pitch). . . . . . . . . . . . . . . . . . . . . 194 LQFP48 - Mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 UFQFPN48 - Mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 Package thermal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 STM32L451xx ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 DS11910 Rev 5 9/207 9 List of figures STM32L451xx List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33. Figure 34. Figure 35. Figure 36. Figure 37. Figure 38. Figure 39. Figure 40. Figure 41. Figure 42. Figure 43. Figure 44. Figure 45. Figure 46. Figure 47. Figure 48. 10/207 STM32L451xx block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Power supply overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Power-up/down sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Clock tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Voltage reference buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 STM32L451Vx LQFP100 pinout(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 STM32L451Vx UFBGA100 ballout(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 STM32L451Rx LQFP64 pinout(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 STM32L451Rx UFBGA64 ballout(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 STM32L451Rx WLCSP64 pinout(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 STM32L451Cx LQFP48 pinout(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 STM32L451Cx UFQFPN48 pinout(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 STM32L451xx memory map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Pin loading conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Pin input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Power supply scheme. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Current consumption measurement scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 VREFINT versus temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 High-speed external clock source AC timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Low-speed external clock source AC timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Typical application with an 8 MHz crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 Typical application with a 32.768 kHz crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 HSI16 frequency versus temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Typical current consumption versus MSI frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 HSI48 frequency versus temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 I/O input characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 I/O AC characteristics definition(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Recommended NRST pin protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 ADC accuracy characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 Typical connection diagram using the ADC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 12-bit buffered / non-buffered DAC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 SPI timing diagram - slave mode and CPHA = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 SPI timing diagram - slave mode and CPHA = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 SPI timing diagram - master mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Quad SPI timing diagram - SDR mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 Quad SPI timing diagram - DDR mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 SAI master timing waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 SAI slave timing waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 SDIO high-speed mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 SD default mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 LQFP100 - Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 LQFP100 - Recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 LQFP100 marking (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 UFBGA100 -Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 UFBGA100 - Recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 UFBGA100 marking (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 LQFP64 - Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 LQFP64 - Recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 DS11910 Rev 5 STM32L451xx Figure 49. Figure 50. Figure 51. Figure 52. Figure 53. Figure 54. Figure 55. Figure 56. Figure 57. Figure 58. Figure 59. Figure 60. Figure 61. Figure 62. List of figures LQFP64 marking (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 UFBGA64 - Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 UFBGA64 - Recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 UFBGA64 marking (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 WLCSP64 - Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 WLCSP64 - Recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 WLCSP64 marking (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 LQFP48 - Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195 LQFP48 - Recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 LQFP48 marking (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 UFQFPN48 - Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 UFQFPN48 - Recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 UFQFPN48 marking (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 LQFP64 PD max vs. TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 DS11910 Rev 5 11/207 11 Introduction 1 STM32L451xx Introduction This datasheet provides the ordering information and mechanical device characteristics of the STM32L451xx microcontrollers. This document should be read in conjunction with the STM32L41x, STM32L42x, STM32L43x, STM32L44x, STM32L45x, STM32L46x reference manual (RM0394), available from the STMicroelectronics website www.st.com. For information on the Arm®(a) Cortex®-M4 core, refer to the Cortex®-M4 Technical Reference Manual, available from the www.arm.com website. a. Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere. 12/207 DS11910 Rev 5 STM32L451xx 2 Description Description The STM32L451xx devices are ultra-low-power microcontrollers based on the high-performance Arm® Cortex®-M4 32-bit RISC core operating at a frequency of up to 80 MHz. The Cortex-M4 core features a Floating point unit (FPU) single precision that supports all Arm® single-precision data-processing instructions and data types. It also implements a full set of DSP instructions and a memory protection unit (MPU) which enhances application security. The STM32L451xx devices embed high-speed memories (Flash memory up to 512 Kbyte, 160 Kbyte of SRAM), a Quad SPI Flash memories interface (available on all packages) and an extensive range of enhanced I/Os and peripherals connected to two APB buses, two AHB buses and a 32-bit multi-AHB bus matrix. The STM32L451xx devices embed several protection mechanisms for embedded Flash memory and SRAM: readout protection, write protection, proprietary code readout protection and Firewall. The devices offer a fast 12-bit ADC (5 Msps), two comparators, one operational amplifier, one DAC channel, an internal voltage reference buffer, a low-power RTC, one generalpurpose 32-bit timer, one 16-bit PWM timer dedicated to motor control, four general-purpose 16-bit timers, and two 16-bit low-power timers. In addition, up to 21 capacitive sensing channels are available. They also feature standard and advanced communication interfaces, namely four I2Cs, three SPIs, three USARTs, one UART and one Low-Power UART, one SAI, one SDMMC, one CAN. The STM32L451xx operates in the -40 to +85 °C (+105 °C junction) and -40 to +125 °C (+130 °C junction) temperature ranges from a 1.71 to 3.6 V power supply. A comprehensive set of power-saving modes makes possible the design of low-power applications. Some independent power supplies are supported: analog independent supply input for ADC, DAC, OPAMP and comparators. A VBAT input makes it possible to backup the RTC and backup registers. The STM32L451xx family offers six packages from 48 to 100-pin packages. DS11910 Rev 5 13/207 56 Description STM32L451xx Table 2. STM32L451xx family device features and peripheral counts Peripheral Flash memory STM32L451Vx 256KB STM32L451Rx 512KB 256KB SRAM 256KB 512KB Yes Advanced control 1 (16-bit) General purpose 2 (16-bit) 1 (32-bit) Basic 2 (16-bit) Low -power 2 (16-bit) SysTick timer 1 Watchdog timers (independent, window) 2 SPI 3 I2C 4 USART UART Comm. interfaces LPUART 3 1 1 SAI 1 CAN 1 SDMMC Yes RTC Tamper pins No Yes 3 Random generator 2 2 Yes GPIOs Wakeup pins 83 5 52 4 38 3 Capacitive sensing Number of channels 21 12 6 12-bit ADC Number of channels 1 16 1 16 1 10 12-bit DAC channels Internal voltage reference buffer 1 No Yes Analog comparator 2 Operational amplifiers 1 Max. CPU frequency 80 MHz Operating voltage 14/207 512KB 160KB Quad SPI Timers STM32L451Cx 1.71 to 3.6 V DS11910 Rev 5 STM32L451xx Description Table 2. STM32L451xx family device features and peripheral counts (continued) Peripheral STM32L451Vx STM32L451Cx Ambient operating temperature: -40 to 85 °C / -40 to 125 °C Junction temperature: -40 to 105 °C / -40 to 130 °C Operating temperature Packages STM32L451Rx LQFP100 UFBGA100 DS11910 Rev 5 WLCSP64 LQFP64 UFBGA64 LQFP48 UFQFPN48 15/207 56 Description STM32L451xx Figure 1. STM32L451xx block diagram D0[3:0], D1[3:0], CLK0, CLK1 CS NJTRST, JTDI, JTCK/SWCLK Quad SPI memory interface JTAG & SW MPU ETM NVIC JTDO/SWD, JTDO TRACECLK D-BUS TRACED[3:0] ARM Cortex-M4 80 MHz FPU I-BUS ART ACCEL/ CACHE RNG Flash up to 512 KB AHB bus-matrix S-BUS SRAM2 32 KB SRAM1 128 KB VDD AHB2 80 MHz DMA2 Power management Voltage regulator 3.3 to 1.2 V VDD = 1.71 to 3.6 V VSS DMA1 @ VDD @ VDD 7 Groups of 4 channels max as AF supervision RC HSI Touch sensing controller Supply reset MSI VDDUSB Int BOR VDDA, VSSA RC LSI PA[15:0] VDD, VSS, NRST GPIO PORT A GPIO PORT B GPIO PORT C PLL 1&2 AHB1 80 MHz PB[15:0] PC[15:0] PVD, PVM @VDD HSI48 OSC_IN XTAL OSC OSC_OUT 4- 16MHz IWDG PD[15:0] GPIO PORT D PE[15:0] GPIO PORT E VBAT = 1.55 to 3.6 V Standby PH[1:0], PH[3] interface Reset & clock M AN AGT control @VBAT GPIO PORT H XTAL 32 kHz OSC32_IN OSC32_OUT PCLKx HCLKx FCLK RTC RTC_TS AWU Backup register RTC_TAMPx RTC_OUT @ VDD TIM2 U STemperature AR T 2 M sensor Bps CRC 32b 4 channels, ETR as AF @ VDDA ADC1 16 external analog inputs ITF CRS_SYNC CRS @ VDDA USART2 VREF+ VREF Buffer 83 AF AHB/APB2 AHB/APB1 USART3 D[7:0] CMD, CK as AF SDIO / MMC FIFO EXT IT. WKUP 3 compl. channels (TIM1_CH[1:3]N), 4 channels (TIM1_CH[1:4]), ETR, BKIN, BKIN2 as AF TIM1 / PWM 16b UART4 smcard IrDA smcard RX, TX, CK, CTS, RTS as AF RX, TX, CK, CTS, RTS as AF IrDA RX, TX, CTS, RTS as AF IrDA SPI2 MOSI, MISO, SCK, NSS as AF SPI3 MOSI, MISO, SCK, NSS as AF WWDG TIM16 RX, TX, CK,CTS, RTS as AF smcard 16b USART1 IrDA MOSI, MISO, SCK, NSS as AF TIM6 16b SPI1 MCLK_A, SD_A, FS_A, SCK_A, EXTCLK MCLK_B, SD_B, FS_B, SCK_B as AF SAI1 SDCKIN[3:0], SDDATIN[3:0], SDCKOUT, SDTRIG as AF SCL, SDA, SMBA as AF I2C3/SMBUS SCL, SDA, SMBA as AF I2C4/SMBUS SCL, SDA, SMBA as AF bxCAN1 FIFO 1 channel, 1 compl. channel, BKIN as AF SCL, SDA, SMBA as AF I2C2/SMBUS 16b APB1 80 MHz (max) TIM15 APB2 80MHz 2 channels, 1 compl. channel, BKIN as AF I2C1/SMBUS TX, RX as AF @VDDA OpAmp1 VOUT, VINM, VINP LPUART1 RX, TX, CTS, RTS as AF SWPMI1 IO RX, TX, SUSPEND as AF LPTIM1 IN1, IN2, OUT, ETR as AF LPTIM2 IN1, OUT, ETR as AF A 60 DFSDM @ VDDA @ VDDA INP, INM, OUT COMP1 INP, INM, OUT COMP2 DAC1 ITF FIREWALL OUT1 Note: 16/207 AF: alternate function on I/O pins. DS11910 Rev 5 MSv40109V1 STM32L451xx Functional overview 3 Functional overview 3.1 Arm® Cortex®-M4 core with FPU The Arm® Cortex®-M4 with FPU processor is the latest generation of Arm® processors for embedded systems, developed to provide a low-cost platform that meets the needs of MCU implementation with a reduced pin count and low-power consumption, while delivering outstanding computational performance and an advanced response to interrupts. The Arm® Cortex®-M4 with FPU 32-bit RISC processor features exceptional codeefficiency, delivering the high-performance expected from an Arm® core in the memory size usually associated with 8- and 16-bit devices. The processor supports a set of DSP instructions enabling efficient signal processing and complex algorithm execution. Its single precision FPU speeds up software development by using metalanguage development tools, while avoiding saturation. With its embedded Arm® core, the STM32L451xx family is compatible with all Arm® tools and software. Figure 1 shows the general block diagram of the STM32L451xx family devices. 3.2 Adaptive real-time memory accelerator (ART Accelerator™) The ART Accelerator™ is a memory accelerator optimized for STM32 industry-standard Arm® Cortex®-M4 processors. It balances the inherent performance advantage of the Arm® Cortex®-M4 over Flash memory technologies, which normally requires the processor to wait for the Flash memory at higher frequencies. To release the processor near 100 DMIPS performance at 80 MHz, the accelerator implements an instruction prefetch queue and branch cache, which increases program execution speed from the 64-bit Flash memory. Based on CoreMark benchmark, the performance achieved thanks to the ART accelerator is equivalent to 0 wait state program execution from Flash memory at a CPU frequency up to 80 MHz. 3.3 Memory protection unit The memory protection unit (MPU) is used to manage the CPU accesses to memory to prevent one task to accidentally corrupt the memory or resources used by any other active task. This memory area is organized into up to 8 protected areas that can in turn be divided up into 8 subareas. The protection area sizes are between 32 bytes and the whole 4 Gigabytes of addressable memory. The MPU is especially helpful for applications where some critical or certified code has to be protected against the misbehavior of other tasks. It is usually managed by an RTOS (realtime operating system). If a program accesses a memory location that is prohibited by the MPU, the RTOS can detect it and take action. In an RTOS environment, the kernel can dynamically update the MPU area setting, based on the process to be executed. The MPU is optional and can be bypassed for applications that do not need it. DS11910 Rev 5 17/207 56 Functional overview 3.4 STM32L451xx Embedded Flash memory STM32L451xx devices feature up to 512 Kbyte of embedded Flash memory available for storing programs and data in single bank architecture. The Flash memory contains 256 pages of 2 Kbyte. Flexible protections can be configured thanks to option bytes: • Readout protection (RDP) to protect the whole memory. Three levels are available: – Level 0: no readout protection – Level 1: memory readout protection: the Flash memory cannot be read from or written to if either debug features are connected, boot in RAM or bootloader is selected – Level 2: chip readout protection: debug features (Cortex-M4 JTAG and serial wire), boot in RAM and bootloader selection are disabled (JTAG fuse). This selection is irreversible. Table 3. Access status versus readout protection level and execution modes Area Debug, boot from RAM or boot from system memory (loader) User execution Protection level Read Write Erase Read Write Erase Main memory 1 Yes Yes Yes No No No 2 Yes Yes Yes N/A N/A N/A System memory 1 Yes No No Yes No No 2 Yes No No N/A N/A N/A Option bytes 1 Yes Yes Yes Yes Yes Yes 2 Yes No No N/A N/A N/A No No N/A(1) Backup registers SRAM2 (1) 1 Yes Yes N/A 2 Yes Yes N/A N/A N/A N/A 1 Yes Yes Yes(1) No No No(1) 2 Yes Yes Yes N/A N/A N/A 1. Erased when RDP change from Level 1 to Level 0. • Write protection (WRP): the protected area is protected against erasing and programming. Two areas can be selected, with 2-Kbyte granularity. • Proprietary code readout protection (PCROP): a part of the flash memory can be protected against read and write from third parties. The protected area is execute-only: it can only be reached by the STM32 CPU, as an instruction code, while all other accesses (DMA, debug and CPU data read, write and erase) are strictly prohibited. The PCROP area granularity is 64-bit wide. An additional option bit (PCROP_RDP) allows the user to select if the PCROP area is erased or not when the RDP protection is changed from Level 1 to Level 0. The whole non-volatile memory embeds the error correction code (ECC) feature supporting: 18/207 • single error detection and correction • double error detection. DS11910 Rev 5 STM32L451xx Functional overview The address of the ECC fail can be read in the ECC register. 3.5 Embedded SRAM STM32L451xx devices feature 160 Kbyte of embedded SRAM, split into two blocks: • 128 Kbyte mapped at address 0x2000 0000 (SRAM1) • 32 Kbyte located at address 0x1000 0000 with hardware parity check (SRAM2). This memory is also mapped at address 0x2002 0000, offering a contiguous address space with the SRAM1 (32 Kbyte aliased by bit band) This block is accessed through the ICode/DCode buses for maximum performance. These 32 Kbyte SRAM can also be retained in Standby mode. The SRAM2 can be write-protected with 1 Kbyte granularity. The memory can be accessed in read/write at CPU clock speed with 0 wait states. 3.6 Firewall The device embeds a Firewall which protects code sensitive and secure data from any access performed by a code executed outside of the protected areas. Each illegal access generates a reset which kills immediately the detected intrusion. The Firewall main features are the following: • Three segments can be protected and defined thanks to the Firewall registers: – Code segment (located in Flash or SRAM1 if defined as executable protected area) – Non-volatile data segment (located in Flash) – Volatile data segment (located in SRAM1) • The start address and the length of each segments are configurable: – Code segment: up to 1024 Kbyte with granularity of 256 bytes – Non-volatile data segment: up to 1024 Kbyte with granularity of 256 bytes – Volatile data segment: up to 128 Kbyte with a granularity of 64 bytes • Specific mechanism implemented to open the Firewall to get access to the protected areas (call gate entry sequence) • Volatile data segment can be shared or not with the non-protected code • Volatile data segment can be executed or not depending on the Firewall configuration The Flash readout protection must be set to level 2 in order to reach the expected level of protection. 3.7 Boot modes At startup, BOOT0 pin or nSWBOOT0 option bit, and BOOT1 option bit are used to select one of three boot options: • Boot from user Flash • Boot from system memory • Boot from embedded SRAM DS11910 Rev 5 19/207 56 Functional overview STM32L451xx BOOT0 value may come from the PH3-BOOT0 pin or from an option bit depending on the value of a user option bit to free the GPIO pad if needed. A Flash empty check mechanism is implemented to force the boot from system flash if the first flash memory location is not programmed and if the boot selection is configured to boot from main flash. The boot loader is located in system memory. It is used to reprogram the Flash memory by using USART, I2C, SPI or CAN. 3.8 Cyclic redundancy check calculation unit (CRC) The CRC (cyclic redundancy check) calculation unit is used to get a CRC code using a configurable generator polynomial value and size. Among other applications, CRC-based techniques are used to verify data transmission or storage integrity. In the scope of the EN/IEC 60335-1 standard, they offer a means of verifying the Flash memory integrity. The CRC calculation unit helps compute a signature of the software during runtime, to be compared with a reference signature generated at linktime and stored at a given memory location. 3.9 Power supply management 3.9.1 Power supply schemes • VDD = 1.71 to 3.6 V: external power supply for I/Os (VDDIO1), the internal regulator and the system analog such as reset, power management and internal clocks. It is provided externally through VDD pins. • VDDA = 1.62 V (ADC/COMPs) / 1.8 (DAC/OPAMP) / 2.4 V (VREFBUF) to 3.6 V: external analog power supply for ADC, DAC, OPAMP, Comparators and Voltage reference buffer. The VDDA voltage level is independent from the VDD voltage. • VBAT = 1.55 to 3.6 V: power supply for RTC, external clock 32 kHz oscillator and backup registers (through power switch) when VDD is not present. Note: When the functions supplied by VDDA are not used, this supply should preferably be shorted to VDD. Note: If these supplies are tied to ground, the I/Os supplied by these power supplies are not 5 V tolerant. Note: VDDIOx is the I/Os general purpose digital functions supply. VDDIOx represents VDDIO1, with VDDIO1 = VDD. 20/207 DS11910 Rev 5 STM32L451xx Functional overview Figure 2. Power supply overview VDDA domain VDDA VSSA A/D converters Comparators D/A converters Operational amplifiers Voltage reference buffer VDD domain VDD VDDIO1 I/O ring Reset block Temp. sensor PLL, HSI, MSI, HSI48 VSS Standby circuitry (Wakeup logic, IWDG) Voltage regulator VCORE VCORE domain Core Memories Digital peripherals Low voltage detector Backup domain VBAT LSE crystal 32 K osc BKP registers RCC BDCR register RTC MSv39205V2 During power-up and power-down phases, the following power sequence requirements must be respected: • When VDD is below 1 V, other power supplies (VDDA) must remain below VDD + 300 mV. • When VDD is above 1 V, all power supplies are independent. During the power-down phase, VDD can temporarily become lower than other supplies only if the energy provided to the MCU remains below 1 mJ; this allows external decoupling capacitors to be discharged with different time constants during the power-down transient phase. DS11910 Rev 5 21/207 56 Functional overview STM32L451xx Figure 3. Power-up/down sequence V 3.6 VDDX(1) VDD VBOR0 1 0.3 Power-on Invalid supply area Operating mode VDDX < VDD + 300 mV Power-down time VDDX independent from VDD MSv47490V1 1. VDDX refers to VDDA. 3.9.2 Power supply supervisor The device has an integrated ultra-low-power brown-out reset (BOR) active in all modes except Shutdown and ensuring proper operation after power-on and during power down. The device remains in reset mode when the monitored supply voltage VDD is below a specified threshold, without the need for an external reset circuit. The lowest BOR level is 1.71V at power on, and other higher thresholds can be selected through option bytes.The device features an embedded programmable voltage detector (PVD) that monitors the VDD power supply and compares it to the VPVD threshold. An interrupt can be generated when VDD drops below the VPVD threshold and/or when VDD is higher than the VPVD threshold. The interrupt service routine can then generate a warning message and/or put the MCU into a safe state. The PVD is enabled by software. In addition, the device embeds a Peripheral Voltage Monitor which compares the independent supply voltage VDDA with a fixed threshold in order to ensure that the peripheral is in its functional supply range. 22/207 DS11910 Rev 5 STM32L451xx 3.9.3 Functional overview Voltage regulator Two embedded linear voltage regulators supply most of the digital circuitries: the main regulator (MR) and the low-power regulator (LPR). • The MR is used in the Run and Sleep modes and in the Stop 0 mode. • The LPR is used in Low-Power Run, Low-Power Sleep, Stop 1 and Stop 2 modes. It is also used to supply the 32 Kbyte SRAM2 in Standby with SRAM2 retention. • Both regulators are in power-down in Standby and Shutdown modes: the regulator output is in high impedance, and the kernel circuitry is powered down thus inducing zero consumption. The ultralow-power STM32L451xx supports dynamic voltage scaling to optimize its power consumption in run mode. The voltage from the Main Regulator that supplies the logic (VCORE) can be adjusted according to the system’s maximum operating frequency. There are two power consumption ranges: • Range 1 with the CPU running at up to 80 MHz. • Range 2 with a maximum CPU frequency of 26 MHz. All peripheral clocks are also limited to 26 MHz. The VCORE can be supplied by the low-power regulator, the main regulator being switched off. The system is then in Low-power run mode. • 3.9.4 Low-power run mode with the CPU running at up to 2 MHz. Peripherals with independent clock can be clocked by HSI16. Low-power modes The ultra-low-power STM32L451xx supports seven low-power modes to achieve the best compromise between low-power consumption, short startup time, available peripherals and available wakeup sources. DS11910 Rev 5 23/207 56 Mode Run LPRun Sleep LPSleep Regulator(1) MR range 1 MR range2 LPR MR range 1 MR range2 LPR DS11910 Rev 5 Flash SRAM Clocks Yes ON(4) ON Any Yes ON(4) ON Any except PLL No ON(4) ON(5) Any No ON(4) ON(5) Any except PLL All except RNG Any interrupt or event LSE LSI BOR, PVD, PVM RTC, IWDG COMPx (x=1,2) DAC1 OPAMPx (x=1) USARTx (x=1...3)(6) UART4(6) LPUART1(6) I2Cx (x=1...4)(7) LPTIMx (x=1,2) *** All other peripherals are frozen. Reset pin, all I/Os BOR, PVD, PVM RTC, IWDG COMPx (x=1..2) USARTx (x=1...3)(6) UART4(6) LPUART1(6) I2Cx (x=1...4)(7) LPTIMx (x=1,2) MR Range 1 Stop 0 No MR Range 2 DMA & Peripherals(2) CPU OFF ON All All except RNG Wakeup source N/A Consumption(3) 94 µA/MHz 85 µA/MHz All except RNG N/A 95 µA/MHz All Any interrupt or event 27 µA/MHz All except RNG 27 µA/MHz 38 µA/MHz Wakeup time N/A to Range 1: 4 µs to Range 2: 64 µs Functional overview 24/207 Table 4. STM32L451xx modes overview 6 cycles 6 cycles 125 µA 2.47 µs in SRAM 4.1 µs in Flash 125 µA STM32L451xx Mode Stop 1 DS11910 Rev 5 Stop 2 Regulator LPR LPR CPU No No DMA & Peripherals(2) Wakeup source Consumption(3) Wakeup time LSE LSI BOR, PVD, PVM RTC, IWDG COMPx (x=1,2) DAC1 OPAMPx (x=1) USARTx (x=1...3)(6) UART4(6) LPUART1(6) I2Cx (x=1...4)(7) LPTIMx (x=1,2) *** All other peripherals are frozen. Reset pin, all I/Os BOR, PVD, PVM RTC, IWDG COMPx (x=1..2) USARTx (x=1...3)(6) UART4(6) LPUART1(6) I2Cx (x=1...4)(7) LPTIMx (x=1,2) 9.85 µA w/o RTC 10.5 µA w RTC 5.7 µs in SRAM 7 µs in Flash LSE LSI BOR, PVD, PVM RTC, IWDG COMPx (x=1..2) I2C3(7) LPUART1(6) LPTIM1 *** All other peripherals are frozen. Reset pin, all I/Os BOR, PVD, PVM RTC, IWDG COMPx (x=1..2) I2C3(7) LPUART1(6) LPTIM1 2.05 µA w/o RTC 2.30 µA w/RTC 5.8 µs in SRAM 8.3 µs in Flash Flash SRAM Clocks Off Off ON ON STM32L451xx Table 4. STM32L451xx modes overview (continued) (1) Functional overview 25/207 Mode Regulator CPU Flash SRAM Clocks Standby OFF Shutdown OFF Power ed Off Power ed Off Off Off Power ed Off Power ed Off Wakeup source Consumption(3) Wakeup time 0.35 µA w/o RTC 0.52 µA w/ RTC DS11910 Rev 5 LSE LSI BOR, RTC, IWDG *** All other peripherals are powered off. *** I/O configuration can be floating, pull-up or pull-down Reset pin 5 I/Os (WKUPx)(8) BOR, RTC, IWDG LSE RTC *** All other peripherals are powered off. *** I/O configuration can be floating, pull-up or pulldown(9) Reset pin 5 I/Os (WKUPx)(8) RTC SRAM 2 ON LPR DMA & Peripherals(2) 0.10 µA w/o RTC 0.27 µA w/ RTC 0.02 µA w/o RTC 0.17 µA w/ RTC 16.1 µs Functional overview 26/207 Table 4. STM32L451xx modes overview (continued) (1) 256 µs 1. LPR means Main regulator is OFF and Low-power regulator is ON. 2. All peripherals can be active or clock gated to save power consumption. 3. Typical current at VDD = 1.8 V, 25°C. Consumptions values provided running from SRAM, Flash memory Off, 80 MHz in Range 1, 26 MHz in Range 2, 2 MHz in LPRun/LPSleep. 4. The Flash memory can be put in power-down and its clock can be gated off when executing from SRAM. 5. The SRAM1 and SRAM2 clocks can be gated on or off independently. 6. U(S)ART and LPUART reception is functional in Stop mode, and generates a wakeup interrupt on Start, address match or received frame event. 7. I2C address detection is functional in Stop mode, and generates a wakeup interrupt in case of address match. 8. The I/Os with wakeup from Standby/Shutdown capability are: PA0, PC13, PE6, PA2, PC5. 9. I/Os can be configured with internal pull-up, pull-down or floating in Shutdown mode but the configuration is lost when exiting the Shutdown mode. STM32L451xx STM32L451xx Functional overview By default, the microcontroller is in Run mode after a system or a power Reset. It is up to the user to select one of the low-power modes described below: • Sleep mode In Sleep mode, only the CPU is stopped. All peripherals continue to operate and can wake up the CPU when an interrupt/event occurs. • Low-power run mode This mode is achieved with VCORE supplied by the low-power regulator to minimize the regulator's operating current. The code can be executed from SRAM or from Flash, and the CPU frequency is limited to 2 MHz. The peripherals with independent clock can be clocked by HSI16. • Low-power sleep mode This mode is entered from the low-power run mode. Only the CPU clock is stopped. When wakeup is triggered by an event or an interrupt, the system reverts to the lowpower run mode. • Stop 0, Stop 1 and Stop 2 modes Stop mode achieves the lowest power consumption while retaining the content of SRAM and registers. All clocks in the VCORE domain are stopped, the PLL, the MSI RC, the HSI16 RC and the HSE crystal oscillators are disabled. The LSE or LSI is still running. The RTC can remain active (Stop mode with RTC, Stop mode without RTC). Some peripherals with wakeup capability can enable the HSI16 RC during Stop mode to detect their wakeup condition. Three Stop modes are available: Stop 0, Stop 1 and Stop 2 modes. In Stop 2 mode, most of the VCORE domain is put in a lower leakage mode. Stop 1 offers the largest number of active peripherals and wakeup sources, a smaller wakeup time but a higher consumption than Stop 2. In Stop 0 mode, the main regulator remains ON, allowing a very fast wakeup time but with much higher consumption. The system clock when exiting from Stop 0, Stop 1 or Stop 2 modes can be either MSI up to 48 MHz or HSI16, depending on software configuration. • Standby mode The Standby mode is used to achieve the lowest power consumption with BOR. The internal regulator is switched off so that the VCORE domain is powered off. The PLL, the MSI RC, the HSI16 RC and the HSE crystal oscillators are also switched off. The RTC can remain active (Standby mode with RTC, Standby mode without RTC). The brown-out reset (BOR) always remains active in Standby mode. The state of each I/O during standby mode can be selected by software: I/O with internal pull-up, internal pull-down or floating. After entering Standby mode, SRAM1 and register contents are lost except for registers in the Backup domain and Standby circuitry. Optionally, SRAM2 can be retained in Standby mode, supplied by the low-power Regulator (Standby with SRAM2 retention mode). The device exits Standby mode when an external reset (NRST pin), an IWDG reset, WKUP pin event (configurable rising or falling edge), or an RTC event occurs (alarm, periodic wakeup, timestamp, tamper) or a failure is detected on LSE (CSS on LSE). The system clock after wakeup is MSI up to 8 MHz. DS11910 Rev 5 27/207 56 Functional overview • STM32L451xx Shutdown mode The Shutdown mode permits to achieve the lowest power consumption. The internal regulator is switched off so that the VCORE domain is powered off. The PLL, the HSI16, the MSI, the LSI and the HSE oscillators are also switched off. The RTC can remain active (Shutdown mode with RTC, Shutdown mode without RTC). The BOR is not available in Shutdown mode. No power voltage monitoring is possible in this mode, therefore the switch to Backup domain is not supported. SRAM1, SRAM2 and register contents are lost except for registers in the Backup domain. The device exits Shutdown mode when an external reset (NRST pin), a WKUP pin event (configurable rising or falling edge), or an RTC event occurs (alarm, periodic wakeup, timestamp, tamper). The system clock after wakeup is MSI at 4 MHz. 28/207 DS11910 Rev 5 STM32L451xx Functional overview Table 5. Functionalities depending on the working mode(1) - - Y - Y - - - - - - - - - - O(2) O(2) O(2) O(2) - - - - - - - - - SRAM1 (128 KB) Y Y(3) Y Y(3) Y - Y - - - - - - SRAM2 (32 KB) Y Y(3) Y Y(3) Y - Y - O(4) - - - - Quad SPI O O O O - - - - - - - - - Backup registers Y Y Y Y Y - Y - Y - Y - Y Brown-out reset (BOR) Y Y Y Y Y Y Y Y Y Y - - - Programmable voltage detector (PVD) O O O O O O O O - - - - - Peripheral voltage monitor (PVMx; x=1,3,4) O O O O O O O O - - - - - DMA O O O O - - - - - - - - - High speed Internal (HSI16) O O O O (5) - (5) - - - - - - Oscillator RC48 O O - - - - - - - - - - - High speed external (HSE) O O O O - - - - - - - - - Low speed internal (LSI) O O O O O - O - O - - - - Low speed external (LSE) O O O O O - O - O - O - O Multi-Speed internal (MSI) O O O O - - - - - - - - - Clock security system (CSS) O O O O - - - - - - - - - Clock security system on LSE O O O O O O O O O O - - - RTC / Auto wakeup O O O O O O O O O O O O O Number of RTC Tamper pins 3 3 3 3 3 O 3 O 3 O 3 O 3 Peripheral CPU Flash memory (up to 512 KB) Run Sleep Lowpower run Lowpower sleep - DS11910 Rev 5 Wakeup capability - Wakeup capability Standby Shutdown Wakeup capability Stop 2 Wakeup capability Stop 0/1 VBAT 29/207 56 Functional overview STM32L451xx Table 5. Functionalities depending on the working mode(1) (continued) Lowpower run Lowpower sleep - - - - - - - Wakeup capability Sleep Standby Shutdown Wakeup capability Run Stop 2 Wakeup capability Peripheral Wakeup capability Stop 0/1 - - - - VBAT USARTx (x=1,2,3) UART4 O O O O O(6) O(6) Low-power UART (LPUART) O O O O O(6) O(6) O(6) O(6) - - - - - I2Cx (x=1,2,4) O O O O O(7) O(7) (7) - - - - - - - O(7) O(7) O(7) - - - - - I2C3 O O O O O SPIx (x=1,2,3) O O O O - - - - - - - - - CAN O O O O - - - - - - - - - SDMMC1 O O O O - - - - - - - - - SAIx (x=1) O O O O - - - - - - - - - DFSDM1 O O O O - - - - - - - - - ADCx (x=1) O O O O - - - - - - - - - DAC1 O O O O O - - - - - - - - VREFBUF O O O O O - - - - - - - - OPAMPx (x=1) O O O O O - - - - - - - - COMPx (x=1,2) O O O O O O O O - - - - - Temperature sensor O O O O - - - - - - - - - Timers (TIMx) O O O O - - - - - - - - - Low-power timer 1 (LPTIM1) O O O O O O O O - - - - - Low-power timer 2 (LPTIM2) O O O O O O - - - - - - - Independent watchdog (IWDG) O O O O O O O O O O - - - Window watchdog (WWDG) O O O O - - - - - - - - - SysTick timer O O O O - - - - - - - - - Touch sensing controller (TSC) O O O O - - - - - - - - - Random number generator (RNG) O(8) O(8) - - - - - - - - - - - 30/207 DS11910 Rev 5 STM32L451xx Functional overview Table 5. Functionalities depending on the working mode(1) (continued) - - CRC calculation unit O O O O - - - - - - - - - GPIOs O O O O O O O O (9) 5 pins (11) 5 pins - Peripheral Run Sleep Lowpower run Lowpower sleep - (10) Wakeup capability - Wakeup capability Standby Shutdown Wakeup capability Stop 2 Wakeup capability Stop 0/1 VBAT (10) 1. Legend: Y = Yes (Enable). O = Optional (Disable by default. Can be enabled by software). - = Not available. 2. The Flash can be configured in power-down mode. By default, it is not in power-down mode. 3. The SRAM clock can be gated on or off. 4. SRAM2 content is preserved when the bit RRS is set in PWR_CR3 register. 5. Some peripherals with wakeup from Stop capability can request HSI16 to be enabled. In this case, HSI16 is woken up by the peripheral, and only feeds the peripheral which requested it. HSI16 is automatically put off when the peripheral does not need it anymore. 6. UART and LPUART reception is functional in Stop mode, and generates a wakeup interrupt on Start, address match or received frame event. 7. I2C address detection is functional in Stop mode, and generates a wakeup interrupt in case of address match. 8. Voltage scaling Range 1 only. 9. I/Os can be configured with internal pull-up, pull-down or floating in Standby mode. 10. The I/Os with wakeup from Standby/Shutdown capability are: PA0, PC13, PE6, PA2, PC5. 11. I/Os can be configured with internal pull-up, pull-down or floating in Shutdown mode but the configuration is lost when exiting the Shutdown mode. 3.9.5 Reset mode In order to improve the consumption under reset, the I/Os state under and after reset is “analog state” (the I/O schmitt trigger is disable). In addition, the internal reset pull-up is deactivated when the reset source is internal. 3.9.6 VBAT operation The VBAT pin permits to power the device VBAT domain from an external battery, an external supercapacitor, or from VDD when no external battery and an external supercapacitor are present. The VBAT pin supplies the RTC with LSE and the backup registers. Three anti-tamper detection pins are available in VBAT mode. VBAT operation is automatically activated when VDD is not present. An internal VBAT battery charging circuit is embedded and can be activated when VDD is present. Note: When the microcontroller is supplied from VBAT, external interrupts and RTC alarm/events do not exit it from VBAT operation. DS11910 Rev 5 31/207 56 Functional overview 3.10 STM32L451xx Interconnect matrix Several peripherals have direct connections between them. This allows autonomous communication between peripherals, saving CPU resources thus power supply consumption. In addition, these hardware connections allow fast and predictable latency. Depending on peripherals, these interconnections can operate in Run, Sleep, low-power run and sleep, Stop 0, Stop 1 and Stop 2 modes. Run Sleep Low-power run Low-power sleep Stop 0 / Stop 1 Stop 2 Table 6. STM32L451xx peripherals interconnect matrix TIMx Timers synchronization or chaining Y Y Y Y - - ADCx DAC1 DFSDM1 Conversion triggers Y Y Y Y - - DMA Memory to memory transfer trigger Y Y Y Y - - COMPx Comparator output blanking Y Y Y Y - - IRTIM Infrared interface output generation Y Y Y Y - - TIM1 TIM2 Timer input channel, trigger, break from analog signals comparison Y Y Y Y - - LPTIMERx Low-power timer triggered by analog signals comparison Y Y Y Y Y (1) TIM1 Timer triggered by analog watchdog Y Y Y Y - - TIM16 Timer input channel from RTC events Y Y Y Y - - LPTIMERx Low-power timer triggered by RTC alarms or tampers Y Y Y Y Y (1) All clocks sources (internal TIM2 and external) TIM15, 16 Clock source used as input channel for RC measurement and trimming Y Y Y Y - - CSS CPU (hard fault) RAM (parity error) Flash memory (ECC error) TIM1 COMPx TIM15,16 PVD DFSDM1 (analog watchdog, short circuit detection) Timer break Y Y Y Y - - Interconnect source TIMx TIM15/TIM16 COMPx ADCx RTC 32/207 Interconnect destination Interconnect action DS11910 Rev 5 Y Y STM32L451xx Functional overview Low-power run Low-power sleep Stop 0 / Stop 1 Stop 2 GPIO Sleep Interconnect source Run Table 6. STM32L451xx peripherals interconnect matrix (continued) TIMx External trigger Y Y Y Y - - LPTIMERx External trigger Y Y Y Y Y (1) ADCx DAC1 DFSDM1 Conversion external trigger Y Y Y Y - - Interconnect destination Interconnect action Y 1. LPTIM1 only. DS11910 Rev 5 33/207 56 Functional overview 3.11 STM32L451xx Clocks and startup The clock controller (see Figure 4) distributes the clocks coming from different oscillators to the core and the peripherals. It also manages clock gating for low-power modes and ensures clock robustness. It features: 34/207 • Clock prescaler: to get the best trade-off between speed and current consumption, the clock frequency to the CPU and peripherals can be adjusted by a programmable prescaler • Safe clock switching: clock sources can be changed safely on the fly in run mode through a configuration register. • Clock management: to reduce power consumption, the clock controller can stop the clock to the core, individual peripherals or memory. • System clock source: four different clock sources can be used to drive the master clock SYSCLK: – 4-48 MHz high-speed external crystal or ceramic resonator (HSE), that can supply a PLL. The HSE can also be configured in bypass mode for an external clock. – 16 MHz high-speed internal RC oscillator (HSI16), trimmable by software, that can supply a PLL – Multispeed internal RC oscillator (MSI), trimmable by software, able to generate 12 frequencies from 100 kHz to 48 MHz. When a 32.768 kHz clock source is available in the system (LSE), the MSI frequency can be automatically trimmed by hardware to reach better than ±0.25% accuracy. The MSI can supply a PLL. – System PLL which can be fed by HSE, HSI16 or MSI, with a maximum frequency at 80 MHz. • RC48 with clock recovery system (HSI48): internal RC48 MHz clock source can be used to drive the SDMMC or the RNG peripherals. This clock can be output on the MCO. • Auxiliary clock source: two ultralow-power clock sources that can be used to drive the real-time clock: – 32.768 kHz low-speed external crystal (LSE), supporting four drive capability modes. The LSE can also be configured in bypass mode for an external clock. – 32 kHz low-speed internal RC (LSI), also used to drive the independent watchdog. The LSI clock accuracy is ±5% accuracy. • Peripheral clock sources: Several peripherals (SDMMC, RNG, SAI, USARTs, I2Cs, LPTimers, ADC) have their own independent clock whatever the system clock. Two PLLs, each having three independent outputs allowing the highest flexibility, can generate independent clocks for the ADC, the SDMMC/RNG and the SAI. • Startup clock: after reset, the microcontroller restarts by default with an internal 4 MHz clock (MSI). The prescaler ratio and clock source can be changed by the application program as soon as the code execution starts. • Clock security system (CSS): this feature can be enabled by software. If a HSE clock failure occurs, the master clock is automatically switched to HSI16 and a software DS11910 Rev 5 STM32L451xx Functional overview interrupt is generated if enabled. LSE failure can also be detected and generated an interrupt. • Clock-out capability: – MCO: microcontroller clock output: it outputs one of the internal clocks for external use by the application. Low frequency clocks (LSI, LSE) are available down to Stop 1 low power state. – LSCO: low speed clock output: it outputs LSI or LSE in all low-power modes down to Standby mode. LSE can also be output on LSCO in Shutdown mode. LSCO is not available in VBAT mode. Several prescalers permit to configure the AHB frequency, the high speed APB (APB2) and the low speed APB (APB1) domains. The maximum frequency of the AHB and the APB domains is 80 MHz. DS11910 Rev 5 35/207 56 Functional overview STM32L451xx Figure 4. Clock tree to IWDG LSI RC 32 kHz LSCO to RTC OSC32_OUT LSE OSC 32.768 kHz /32 OSC32_IN LSE LSI HSE to PWR SYSCLK MCO / 1→16 MSI HSI16 Clock source control HSI48 OSC_OUT HSE OSC 4-48 MHz OSC_IN PLLCLK to AHB bus, core, memory and DMA AHB PRESC / 1,2,..512 HCLK to Cortex system timer HSE Clock detector FCLK Cortex free running clock /8 MSI SYSCLK APB1 PRESC / 1,2,4,8,16 HSI16 PCLK1 to APB1 peripherals x1 or x2 HSI RC 16 MHz LSE HSI16 SYSCLK to USARTx x=2..3 to UART4 to LPUART1 HSI16 SYSCLK MSI RC 100 kHz – 48 MHz to I2Cx x=1,2,3,4 LSI LSE HSI16 MSI PLL /M /P /Q /R /Q /R to LPTIMx x=1,2 PCLK2 HSI16 APB2 PRESC / 1,2,4,8,16 HSE PLLSAI1CLK PLL48M1CLK to APB2 peripherals x1 or x2 PLLCLK PLLSAI1 /P to TIMx x=2,6,7 PLLSAI2CLK to TIMx x=1,15,16 LSE HSI16 SYSCLK to USART1 SYSCLK to DFSDM1 PLL48M2CLK PLLADC1CLK SYSCLK HSI RC 48 MHz HSI16 to ADC MSI CRS 48 MHz clock to RNG, SDMMC HSI16 to SAI1 SAI1_EXTCLK MSv41619V2 36/207 DS11910 Rev 5 STM32L451xx 3.12 Functional overview General-purpose inputs/outputs (GPIOs) Each of the GPIO pins can be configured by software as output (push-pull or open-drain), as input (with or without pull-up or pull-down) or as peripheral alternate function. Most of the GPIO pins are shared with digital or analog alternate functions. Fast I/O toggling can be achieved thanks to their mapping on the AHB2 bus. The I/Os alternate function configuration can be locked if needed following a specific sequence in order to avoid spurious writing to the I/Os registers. 3.13 Direct memory access controller (DMA) The device embeds 2 DMAs. Refer to Table 7: DMA implementation for the features implementation. Direct memory access (DMA) is used in order to provide high-speed data transfer between peripherals and memory as well as memory to memory. Data can be quickly moved by DMA without any CPU actions. This keeps CPU resources free for other operations. The two DMA controllers have 14 channels in total, each dedicated to managing memory access requests from one or more peripherals. Each has an arbiter for handling the priority between DMA requests. The DMA supports: • 14 independently configurable channels (requests) • Each channel is connected to dedicated hardware DMA requests, software trigger is also supported on each channel. This configuration is done by software. • Priorities between requests from channels of one DMA are software programmable (4 levels consisting of very high, high, medium, low) or hardware in case of equality (request 1 has priority over request 2, etc.) • Independent source and destination transfer size (byte, half word, word), emulating packing and unpacking. Source/destination addresses must be aligned on the data size. • Support for circular buffer management • 3 event flags (DMA Half Transfer, DMA Transfer complete and DMA Transfer Error) logically ORed together in a single interrupt request for each channel • Memory-to-memory transfer • Peripheral-to-memory and memory-to-peripheral, and peripheral-to-peripheral transfers • Access to Flash, SRAM, APB and AHB peripherals as source and destination • Programmable number of data to be transferred: up to 65536. Table 7. DMA implementation DMA features DMA1 DMA2 Number of regular channels 7 7 DS11910 Rev 5 37/207 56 Functional overview STM32L451xx 3.14 Interrupts and events 3.14.1 Nested vectored interrupt controller (NVIC) The devices embed a nested vectored interrupt controller able to manage 16 priority levels, and handle up to 67 maskable interrupt channels plus the 16 interrupt lines of the Cortex®M4. The NVIC benefits are the following: • Closely coupled NVIC gives low latency interrupt processing • Interrupt entry vector table address passed directly to the core • Allows early processing of interrupts • Processing of late arriving higher priority interrupts • Support for tail chaining • Processor state automatically saved on interrupt entry, and restored on interrupt exit, with no instruction overhead The NVIC hardware block provides flexible interrupt management features with minimal interrupt latency. 3.14.2 Extended interrupt/event controller (EXTI) The extended interrupt/event controller consists of 37 edge detector lines used to generate interrupt/event requests and wake-up the system from Stop mode. Each external line can be independently configured to select the trigger event (rising edge, falling edge, both) and can be masked independently. A pending register maintains the status of the interrupt requests. The internal lines are connected to peripherals with wakeup from Stop mode capability. The EXTI can detect an external line with a pulse width shorter than the internal clock period. Up to 83 GPIOs can be connected to the 16 external interrupt lines. 38/207 DS11910 Rev 5 STM32L451xx 3.15 Functional overview Analog to digital converter (ADC) The device embeds a successive approximation analog-to-digital converter with the following features: • 12-bit native resolution, with built-in calibration • 5.33 Msps maximum conversion rate with full resolution Down to 18.75 ns sampling time – Increased conversion rate for lower resolution (up to 8.88 Msps for 6-bit resolution) • Up to 16 external channels. • 4 internal channels: internal reference voltage, temperature sensor, VBAT/3 and DAC1_OUT1. • One external reference pin is available on some package, allowing the input voltage range to be independent from the power supply • Single-ended and differential mode inputs • Low-power design • 3.15.1 – – Capable of low-current operation at low conversion rate (consumption decreases linearly with speed) – Dual clock domain architecture: ADC speed independent from CPU frequency Highly versatile digital interface – Single-shot or continuous/discontinuous sequencer-based scan mode: 2 groups of analog signals conversions can be programmed to differentiate background and high-priority real-time conversions – ADC supports multiple trigger inputs for synchronization with on-chip timers and external signals – Results stored into data register or in RAM with DMA controller support – Data pre-processing: left/right alignment and per channel offset compensation – Built-in oversampling unit for enhanced SNR – Channel-wise programmable sampling time – Three analog watchdog for automatic voltage monitoring, generating interrupts and trigger for selected timers – Hardware assistant to prepare the context of the injected channels to allow fast context switching Temperature sensor The temperature sensor (TS) generates a voltage VTS that varies linearly with temperature. The temperature sensor is internally connected to the ADC1_IN17 input channel which is used to convert the sensor output voltage into a digital value. The sensor provides good linearity but it has to be calibrated to obtain good overall accuracy of the temperature measurement. As the offset of the temperature sensor varies from chip to chip due to process variation, the uncalibrated internal temperature sensor is suitable for applications that detect temperature changes only. To improve the accuracy of the temperature sensor measurement, each device is individually factory-calibrated by ST. The temperature sensor factory calibration data are stored by ST in the system memory area, accessible in read-only mode. DS11910 Rev 5 39/207 56 Functional overview STM32L451xx Table 8. Temperature sensor calibration values 3.15.2 Calibration value name Description Memory address TS_CAL1 TS ADC raw data acquired at a temperature of 30 °C (± 5 °C), VDDA = VREF+ = 3.0 V (± 10 mV) 0x1FFF 75A8 - 0x1FFF 75A9 TS_CAL2 TS ADC raw data acquired at a temperature of 130 °C (± 5 °C), VDDA = VREF+ = 3.0 V (± 10 mV) 0x1FFF 75CA - 0x1FFF 75CB Internal voltage reference (VREFINT) The internal voltage reference (VREFINT) provides a stable (bandgap) voltage output for the ADC and Comparators. VREFINT is internally connected to the ADC1_IN0 input channel. The precise voltage of VREFINT is individually measured for each part by ST during production test and stored in the system memory area. It is accessible in read-only mode. Table 9. Internal voltage reference calibration values 3.15.3 Calibration value name Description Memory address VREFINT Raw data acquired at a temperature of 30 °C (± 5 °C), VDDA = VREF+ = 3.0 V (± 10 mV) 0x1FFF 75AA - 0x1FFF 75AB VBAT battery voltage monitoring This embedded hardware feature allows the application to measure the VBAT battery voltage using the internal ADC channel ADC1_IN18 or ADC3_IN18. As the VBAT voltage may be higher than VDDA, and thus outside the ADC input range, the VBAT pin is internally connected to a bridge divider by 3. As a consequence, the converted digital value is one third the VBAT voltage. 3.16 Digital to analog converter (DAC) One 12-bit buffered DAC channel can be used to convert digital signals into analog voltage signal outputs. The chosen design structure is composed of integrated resistor strings and an amplifier in inverting configuration. 40/207 DS11910 Rev 5 STM32L451xx Functional overview This digital interface supports the following features: • Up to two DAC output channels • 8-bit or 12-bit output mode • Buffer offset calibration (factory and user trimming) • Left or right data alignment in 12-bit mode • Synchronized update capability • Noise-wave generation • Triangular-wave generation • Dual DAC channel independent or simultaneous conversions • DMA capability for each channel • External triggers for conversion • Sample and hold low-power mode, with internal or external capacitor The DAC channels are triggered through the timer update outputs that are also connected to different DMA channels. 3.17 Voltage reference buffer (VREFBUF) The STM32L451xx devices embed an voltage reference buffer which can be used as voltage reference for ADCs, DAC and also as voltage reference for external components through the VREF+ pin. The internal voltage reference buffer supports two voltages: • 2.048 V • 2.5 V An external voltage reference can be provided through the VREF+ pin when the internal voltage reference buffer is off. The VREF+ pin is double-bonded with VDDA on some packages. In these packages the internal voltage reference buffer is not available. Figure 5. Voltage reference buffer VREFBUF VDDA Bandgap + DAC, ADC VREF+ Low frequency cut-off capacitor 100 nF MSv40197V1 DS11910 Rev 5 41/207 56 Functional overview 3.18 STM32L451xx Comparators (COMP) The STM32L451xx devices embed two rail-to-rail comparators with programmable reference voltage (internal or external), hysteresis and speed (low speed for low-power) and with selectable output polarity. The reference voltage can be one of the following: • External I/O • DAC output channels • Internal reference voltage or submultiple (1/4, 1/2, 3/4). All comparators can wake up from Stop mode, generate interrupts and breaks for the timers and can be also combined into a window comparator. 3.19 Operational amplifier (OPAMP) The STM32L451xx embeds one operational amplifier with external or internal follower routing and PGA capability. The operational amplifier features: 3.20 • Low input bias current • Low offset voltage • Low-power mode • Rail-to-rail input Touch sensing controller (TSC) The touch sensing controller provides a simple solution for adding capacitive sensing functionality to any application. Capacitive sensing technology is able to detect finger presence near an electrode which is protected from direct touch by a dielectric (such as glass or plastic). The capacitive variation introduced by the finger (or any conductive object) is measured using a proven implementation based on a surface charge transfer acquisition principle. The touch sensing controller is fully supported by the STMTouch touch sensing firmware library which is free to use and allows touch sensing functionality to be implemented reliably in the end application. 42/207 DS11910 Rev 5 STM32L451xx Functional overview The main features of the touch sensing controller are the following: • Proven and robust surface charge transfer acquisition principle • Supports up to 21 capacitive sensing channels • Up to 3 capacitive sensing channels can be acquired in parallel offering a very good response time • Spread spectrum feature to improve system robustness in noisy environments • Full hardware management of the charge transfer acquisition sequence • Programmable charge transfer frequency • Programmable sampling capacitor I/O pin • Programmable channel I/O pin • Programmable max count value to avoid long acquisition when a channel is faulty • Dedicated end of acquisition and max count error flags with interrupt capability • One sampling capacitor for up to 3 capacitive sensing channels to reduce the system components • Compatible with proximity, touchkey, linear and rotary touch sensor implementation • Designed to operate with STMTouch touch sensing firmware library Note: The number of capacitive sensing channels is dependent on the size of the packages and subject to I/O availability. 3.21 Digital filter for Sigma-Delta modulators (DFSDM) The device embeds one DFSDM with 2 digital filters modules and 4 external input serial channels (transceivers) or alternately 4 internal parallel inputs support. The DFSDM peripheral is dedicated to interface the external Σ∆ modulators to microcontroller and then to perform digital filtering of the received data streams (which represent analog value on Σ∆ modulators inputs). DFSDM can also interface PDM (Pulse Density Modulation) microphones and perform PDM to PCM conversion and filtering in DS11910 Rev 5 43/207 56 Functional overview STM32L451xx hardware. DFSDM features optional parallel data stream inputs from microcontrollers memory (through DMA/CPU transfers into DFSDM). DFSDM transceivers support several serial interface formats (to support various Σ∆ modulators). DFSDM digital filter modules perform digital processing according user selected filter parameters with up to 24-bit final ADC resolution. The DFSDM peripheral supports: • 4 multiplexed input digital serial channels: – • – configurable Manchester coded 1 wire interface support – PDM (Pulse Density Modulation) microphone input support – maximum input clock frequency up to 20 MHz (10 MHz for Manchester coding) – clock output for SD modulator(s): 0..20 MHz alternative inputs from 8 internal digital parallel channels (up to 16 bit input resolution): – • internal sources: device memory data streams (DMA) 2 digital filter modules with adjustable digital signal processing: – Sincx filter: filter order/type (1..5), oversampling ratio (up to 1..1024) – integrator: oversampling ratio (1..256) • up to 24-bit output data resolution, signed output data format • automatic data offset correction (offset stored in register by user) • continuous or single conversion • start-of-conversion triggered by: • • – software trigger – internal timers – external events – start-of-conversion synchronously with first digital filter module (DFSDM1_FLT0) analog watchdog feature: – low value and high value data threshold registers – dedicated configurable Sincx digital filter (order = 1..3, oversampling ratio = 1..32) – input from final output data or from selected input digital serial channels – continuous monitoring independently from standard conversion short circuit detector to detect saturated analog input values (bottom and top range): – up to 8-bit counter to detect 1..256 consecutive 0’s or 1’s on serial data stream – monitoring continuously each input serial channel • break signal generation on analog watchdog event or on short circuit detector event • extremes detector: – storage of minimum and maximum values of final conversion data – refreshed by software • DMA capability to read the final conversion data • interrupts: end of conversion, overrun, analog watchdog, short circuit, input serial channel clock absence • “regular” or “injected” conversions: – 44/207 configurable SPI interface to connect various SD modulator(s) “regular” conversions can be requested at any time or even in continuous mode DS11910 Rev 5 STM32L451xx Functional overview without having any impact on the timing of “injected” conversions – “injected” conversions for precise timing and with high conversion priority Table 10. DFSDM1 implementation DFSDM features DFSDM1 Number of channels 8 Number of filters 4 Input from internal ADC - Supported trigger sources 3.22 10 Pulses skipper - ID registers support - Random number generator (RNG) All devices embed an RNG that delivers 32-bit random numbers generated by an integrated analog circuit. 3.23 Timers and watchdogs The STM32L451xx includes one advanced control timers, up to five general-purpose timers, two basic timers, two low-power timers, two watchdog timers and a SysTick timer. The table below compares the features of the advanced control, general purpose and basic timers. Table 11. Timer feature comparison Timer type Timer Counter resolution Counter type Prescaler factor DMA request generation Capture/ compare channels Complementary outputs Advanced control TIM1 16-bit Up, down, Up/down Any integer between 1 and 65536 Yes 4 3 Generalpurpose TIM2 32-bit Up, down, Up/down Any integer between 1 and 65536 Yes 4 No Generalpurpose TIM3 16-bit Up, down, Up/down Any integer between 1 and 65536 Yes 4 No Generalpurpose TIM15 16-bit Up Any integer between 1 and 65536 Yes 2 1 Generalpurpose TIM16 16-bit Up Any integer between 1 and 65536 Yes 1 1 Basic TIM6 16-bit Up Any integer between 1 and 65536 Yes 0 No DS11910 Rev 5 45/207 56 Functional overview 3.23.1 STM32L451xx Advanced-control timer (TIM1) The advanced-control timer can each be seen as a three-phase PWM multiplexed on 6 channels. They have complementary PWM outputs with programmable inserted deadtimes. They can also be seen as complete general-purpose timers. The 4 independent channels can be used for: • Input capture • Output compare • PWM generation (edge or center-aligned modes) with full modulation capability (0100%) • One-pulse mode output In debug mode, the advanced-control timer counter can be frozen and the PWM outputs disabled to turn off any power switches driven by these outputs. Many features are shared with those of the general-purpose TIMx timers (described in Section 3.23.2) using the same architecture, so the advanced-control timer can work together with the TIMx timers via the Timer Link feature for synchronization or event chaining. 3.23.2 General-purpose timers (TIM2, TIM3, TIM15, TIM16) There are up to three synchronizable general-purpose timers embedded in the STM32L451xx (see Table 11 for differences). Each general-purpose timer can be used to generate PWM outputs, or act as a simple time base. • TIM2, TIM3 They are full-featured general-purpose timers: – TIM2 has a 32-bit auto-reload up/downcounter and 32-bit prescaler. – TIM3 has 16-bit auto-reload up/downcounter and 16-bit prescaler. These timers feature 4 independent channels for input capture/output compare, PWM or one-pulse mode output. They can work with the other general-purpose timers via the Timer Link feature for synchronization or event chaining. The counters can be frozen in debug mode. All have independent DMA request generation and support quadrature encoder. • TIM15 and 16 They are general-purpose timers with mid-range features: They have 16-bit auto-reload upcounters and 16-bit prescalers. – TIM15 has 2 channels and 1 complementary channel – TIM16 has 1 channel and 1 complementary channel All channels can be used for input capture/output compare, PWM or one-pulse mode output. The timers can work together via the Timer Link feature for synchronization or event chaining. The timers have independent DMA request generation. The counters can be frozen in debug mode. 3.23.3 Basic timer (TIM6) The basic timer is mainly used for DAC trigger generation. It can also be used as generic 16-bit timebase. 46/207 DS11910 Rev 5 STM32L451xx 3.23.4 Functional overview Low-power timer (LPTIM1 and LPTIM2) The devices embed two low-power timers. These timers have an independent clock and are running in Stop mode if they are clocked by LSE, LSI or an external clock. They are able to wakeup the system from Stop mode. LPTIM1 is active in Stop 0, Stop 1 and Stop 2 modes. LPTIM2 is active in Stop 0 and Stop 1 mode. This low-power timer supports the following features: 3.23.5 • 16-bit up counter with 16-bit autoreload register • 16-bit compare register • Configurable output: pulse, PWM • Continuous/ one shot mode • Selectable software/hardware input trigger • Selectable clock source – Internal clock sources: LSE, LSI, HSI16 or APB clock – External clock source over LPTIM input (working even with no internal clock source running, used by pulse counter application). • Programmable digital glitch filter • Encoder mode (LPTIM1 only) Infrared interface (IRTIM) The STM32L451xx includes one infrared interface (IRTIM), which can be used with an infrared LED to perform remote control functions. It uses TIM15 and TIM16 output channels to generate output signal waveforms on IR_OUT pin. 3.23.6 Independent watchdog (IWDG) The independent watchdog is based on a 12-bit downcounter and 8-bit prescaler. It is clocked from an independent 32 kHz internal RC (LSI) and as it operates independently from the main clock, it can operate in Stop and Standby modes. It can be used either as a watchdog to reset the device when a problem occurs, or as a free running timer for application timeout management. It is hardware or software configurable through the option bytes. The counter can be frozen in debug mode. 3.23.7 System window watchdog (WWDG) The window watchdog is based on a 7-bit downcounter that can be set as free running. It can be used as a watchdog to reset the device when a problem occurs. It is clocked from the main clock. It has an early warning interrupt capability and the counter can be frozen in debug mode. DS11910 Rev 5 47/207 56 Functional overview 3.23.8 STM32L451xx SysTick timer This timer is dedicated to real-time operating systems, but can also be used as a standard down counter. It features: 3.24 • A 24-bit down counter • Autoreload capability • Maskable system interrupt generation when the counter reaches 0 • Programmable clock source Real-time clock (RTC) and backup registers The RTC is an independent BCD timer/counter. It supports the following features: • Calendar with subsecond, seconds, minutes, hours (12 or 24 format), week day, date, month, year, in BCD (binary-coded decimal) format. • Automatic correction for 28, 29 (leap year), 30, and 31 days of the month. • Two programmable alarms. • On-the-fly correction from 1 to 32767 RTC clock pulses. This can be used to synchronize it with a master clock. • Reference clock detection: a more precise second source clock (50 or 60 Hz) can be used to enhance the calendar precision. • Digital calibration circuit with 0.95 ppm resolution, to compensate for quartz crystal inaccuracy. • Three anti-tamper detection pins with programmable filter. • Timestamp feature, which can be used to save the calendar content. This function can be triggered by an event on the timestamp pin, or by a tamper event, or by a switch to VBAT mode. • 17-bit auto-reload wakeup timer (WUT) for periodic events with programmable resolution and period. The RTC and the 32 backup registers are supplied through a switch that takes power either from the VDD supply when present or from the VBAT pin. The backup registers are 32-bit registers used to store 128 bytes of user application data when VDD power is not present. They are not reset by a system or power reset, or when the device wakes up from Standby or Shutdown mode. The RTC clock sources can be: • A 32.768 kHz external crystal (LSE) • An external resonator or oscillator (LSE) • The internal low power RC oscillator (LSI, with typical frequency of 32 kHz) • The high-speed external clock (HSE) divided by 32. The RTC is functional in VBAT mode and in all low-power modes when it is clocked by the LSE. When clocked by the LSI, the RTC is not functional in VBAT mode, but is functional in all low-power modes except Shutdown mode. All RTC events (Alarm, WakeUp Timer, Timestamp or Tamper) can generate an interrupt and wakeup the device from the low-power modes. 48/207 DS11910 Rev 5 STM32L451xx 3.25 Functional overview Inter-integrated circuit interface (I2C) The device embeds four I2C. Refer to Table 12 for the features implementation. The I2C bus interface handles communications between the microcontroller and the serial I2C bus. It controls all I2C bus-specific sequencing, protocol, arbitration and timing. The I2C peripheral supports: • • I2C-bus specification and user manual rev. 5 compatibility: – Slave and master modes, multimaster capability – Standard-mode (Sm), with a bitrate up to 100 kbit/s – Fast-mode (Fm), with a bitrate up to 400 kbit/s – Fast-mode Plus (Fm+), with a bitrate up to 1 Mbit/s and 20 mA output drive I/Os – 7-bit and 10-bit addressing mode, multiple 7-bit slave addresses – Programmable setup and hold times – Optional clock stretching System Management Bus (SMBus) specification rev 2.0 compatibility: – Hardware PEC (Packet Error Checking) generation and verification with ACK control – Address resolution protocol (ARP) support – SMBus alert • Power System Management Protocol (PMBusTM) specification rev 1.1 compatibility • Independent clock: a choice of independent clock sources allowing the I2C communication speed to be independent from the PCLK reprogramming. Refer to Figure 4: Clock tree. • Wakeup from Stop mode on address match • Programmable analog and digital noise filters • 1-byte buffer with DMA capability Table 12. I2C implementation I2C features(1) I2C1 I2C2 I2C3 I2C4 Standard-mode (up to 100 kbit/s) X X X X Fast-mode (up to 400 kbit/s) X X X X Fast-mode Plus with 20mA output drive I/Os (up to 1 Mbit/s) X X X X Programmable analog and digital noise filters X X X X SMBus/PMBus hardware support X X X X Independent clock X X X X Wakeup from Stop 1 mode on address match X X X X Wakeup from Stop 2 mode on address match - - X - 1. X: supported DS11910 Rev 5 49/207 56 Functional overview 3.26 STM32L451xx Universal synchronous/asynchronous receiver transmitter (USART) The STM32L451xx devices have three embedded universal synchronous receiver transmitters (USART1, USART2 and USART3) and one universal asynchronous receiver transmitters (UART4). These interfaces provide asynchronous communication, IrDA SIR ENDEC support, multiprocessor communication mode, single-wire half-duplex communication mode and have LIN Master/Slave capability. They provide hardware management of the CTS and RTS signals, and RS485 Driver Enable, and are able to communicate at speeds of up to 10 Mbit/s. USART1, USART2 and USART3 also provide Smart Card mode (ISO 7816 compliant) and SPI-like communication capability. All USART have a clock domain independent from the CPU clock, allowing the USARTx (x=1,2,3,4) to wake up the MCU from Stop mode using baudrates up to 204 Kbaud. The wake up events from Stop mode are programmable and can be: • Start bit detection • Any received data frame • A specific programmed data frame All USART interfaces can be served by the DMA controller. Table 13. STM32L451xx USART/UART/LPUART features USART modes/features(1) USART1 USART2 USART3 LPUART1 Hardware flow control for modem X X X X X Continuous communication using DMA X X X X X Multiprocessor communication X X X X X Synchronous mode X X X - - Smartcard mode X X X - - Single-wire half-duplex communication X X X X X IrDA SIR ENDEC block X X X X - LIN mode X X X X - Dual clock domain X X X X X Wakeup from Stop 0 / Stop 1 modes X X X X X Wakeup from Stop 2 mode - - - - X Receiver timeout interrupt X X X X - Modbus communication X X X X - Auto baud rate detection Driver Enable X (4 modes) X LPUART/USART data length X X 7, 8 and 9 bits 1. X = supported. 50/207 UART4 DS11910 Rev 5 X X STM32L451xx 3.27 Functional overview Low-power universal asynchronous receiver transmitter (LPUART) The device embeds one Low-Power UART. The LPUART supports asynchronous serial communication with minimum power consumption. It supports half duplex single wire communication and modem operations (CTS/RTS). It allows multiprocessor communication. The LPUART has a clock domain independent from the CPU clock, and can wakeup the system from Stop mode using baudrates up to 220 Kbaud. The wake up events from Stop mode are programmable and can be: • Start bit detection • Any received data frame • A specific programmed data frame Only a 32.768 kHz clock (LSE) is needed to allow LPUART communication up to 9600 baud. Therefore, even in Stop mode, the LPUART can wait for an incoming frame while having an extremely low energy consumption. Higher speed clock can be used to reach higher baudrates. LPUART interface can be served by the DMA controller. DS11910 Rev 5 51/207 56 Functional overview 3.28 STM32L451xx Serial peripheral interface (SPI) Three SPI interfaces allow communication up to 40 Mbits/s in master and up to 24 Mbits/s slave modes, in half-duplex, full-duplex and simplex modes. The 3-bit prescaler gives 8 master mode frequencies and the frame size is configurable from 4 bits to 16 bits. The SPI interfaces support NSS pulse mode, TI mode and Hardware CRC calculation. All SPI interfaces can be served by the DMA controller. 3.29 Serial audio interfaces (SAI) The device embeds 1 SAI. Refer to Table 14: SAI implementation for the features implementation. The SAI bus interface handles communications between the microcontroller and the serial audio protocol. The SAI peripheral supports: • Two independent audio sub-blocks which can be transmitters or receivers with their respective FIFO. • 8-word integrated FIFOs for each audio sub-block. • Synchronous or asynchronous mode between the audio sub-blocks. • Master or slave configuration independent for both audio sub-blocks. • Clock generator for each audio block to target independent audio frequency sampling when both audio sub-blocks are configured in master mode. • Data size configurable: 8-, 10-, 16-, 20-, 24-, 32-bit. • Peripheral with large configurability and flexibility permitting to target as example the following audio protocol: I2S, LSB or MSB-justified, PCM/DSP, TDM, AC’97 and SPDIF out. • Up to 16 slots available with configurable size and with the possibility to select which ones are active in the audio frame. • Number of bits by frame may be configurable. • Frame synchronization active level configurable (offset, bit length, level). • First active bit position in the slot is configurable. • LSB first or MSB first for data transfer. • Mute mode. • Stereo/Mono audio frame capability. • Communication clock strobing edge configurable (SCK). • Error flags with associated interrupts if enabled respectively. • • 52/207 – Overrun and underrun detection. – Anticipated frame synchronization signal detection in slave mode. – Late frame synchronization signal detection in slave mode. – Codec not ready for the AC’97 mode in reception. Interruption sources when enabled: – Errors. – FIFO requests. DMA interface with 2 dedicated channels to handle access to the dedicated integrated FIFO of each SAI audio sub-block. DS11910 Rev 5 STM32L451xx Functional overview Table 14. SAI implementation SAI features Support(1) I2S, LSB or MSB-justified, PCM/DSP, TDM, AC’97 X Mute mode X Stereo/Mono audio frame capability. X 16 slots X Data size configurable: 8-, 10-, 16-, 20-, 24-, 32-bit X FIFO Size X (8 Word) SPDIF X 1. X: supported 3.30 Controller area network (CAN) The CAN is compliant with specifications 2.0A and B (active) with a bit rate up to 1 Mbit/s. It can receive and transmit standard frames with 11-bit identifiers as well as extended frames with 29-bit identifiers. It has three transmit mailboxes, two receive FIFOs with 3 stages and 14 scalable filter banks. The CAN peripheral supports: • Supports CAN protocol version 2.0 A, B Active • Bit rates up to 1 Mbit/s • Transmission • • • 3.31 – Three transmit mailboxes – Configurable transmit priority Reception – Two receive FIFOs with three stages – 14 Scalable filter banks – Identifier list feature – Configurable FIFO overrun Time-triggered communication option – Disable automatic retransmission mode – 16-bit free running timer – Time Stamp sent in last two data bytes Management – Maskable interrupts – Software-efficient mailbox mapping at a unique address space Secure digital input/output and MultiMediaCards Interface (SDMMC) The card host interface (SDMMC) provides an interface between the APB peripheral bus and MultiMediaCards (MMCs), SD memory cards and SDIO cards. DS11910 Rev 5 53/207 56 Functional overview STM32L451xx The SDMMC features include the following: 3.32 • Full compliance with MultiMediaCard System Specification Version 4.2. Card support for three different databus modes: 1-bit (default), 4-bit and 8-bit • Full compatibility with previous versions of MultiMediaCards (forward compatibility) • Full compliance with SD Memory Card Specifications Version 2.0 • Full compliance with SD I/O Card Specification Version 2.0: card support for two different databus modes: 1-bit (default) and 4-bit • Data transfer up to 48 MHz for the 8 bit mode • Data write and read with DMA capability Clock recovery system (CRS) The STM32L451xx devices embed a special block which allows automatic trimming of the internal 48 MHz oscillator to guarantee its optimal accuracy over the whole device operational range. This automatic trimming is based on the external synchronization signal, which could be either derived from LSE oscillator, from an external signal on CRS_SYNC pin or generated by user software. For faster lock-in during startup it is also possible to combine automatic trimming with manual trimming action. 3.33 Quad SPI memory interface (QUADSPI) The Quad SPI is a specialized communication interface targeting single, dual or quad SPI Flash memories. It can operate in any of the three following modes: • Indirect mode: all the operations are performed using the QUADSPI registers • Status polling mode: the external Flash memory status register is periodically read and an interrupt can be generated in case of flag setting • Memory-mapped mode: the external Flash is memory mapped and is seen by the system as if it were an internal memory Both throughput and capacity can be increased two-fold using dual-flash mode, where two Quad SPI flash memories are accessed simultaneously. 54/207 DS11910 Rev 5 STM32L451xx Functional overview The Quad SPI interface supports: • Three functional modes: indirect, status-polling, and memory-mapped • Dual-flash mode, where 8 bits can be sent/received simultaneously by accessing two flash memories in parallel. • SDR and DDR support • Fully programmable opcode for both indirect and memory mapped mode • Fully programmable frame format for both indirect and memory mapped mode • Each of the five following phases can be configured independently (enable, length, single/dual/quad communication) – Instruction phase – Address phase – Alternate bytes phase – Dummy cycles phase – Data phase • Integrated FIFO for reception and transmission • 8, 16, and 32-bit data accesses are allowed • DMA channel for indirect mode operations • Programmable masking for external flash flag management • Timeout management • Interrupt generation on FIFO threshold, timeout, status match, operation complete, and access error DS11910 Rev 5 55/207 56 Functional overview STM32L451xx 3.34 Development support 3.34.1 Serial wire JTAG debug port (SWJ-DP) The Arm® SWJ-DP interface is embedded, and is a combined JTAG and serial wire debug port that enables either a serial wire debug or a JTAG probe to be connected to the target. Debug is performed using only two pins instead of the five required by the JTAG (JTAG pins can be reused as GPIO with alternate function): the JTAG TMS and TCK pins are shared with SWDIO and SWCLK, respectively, and a specific sequence on the TMS pin is used to switch between JTAG-DP and SW-DP. 3.34.2 Embedded Trace Macrocell™ The Arm® Embedded Trace Macrocell™ provides a greater visibility of the instruction and data flow inside the CPU core by streaming compressed data at a very high rate from the STM32L451xx through a small number of ETM pins to an external hardware trace port analyzer (TPA) device. Real-time instruction and data flow activity be recorded and then formatted for display on the host computer that runs the debugger software. TPA hardware is commercially available from common development tool vendors. The Embedded Trace Macrocell™ operates with third party debugger software tools. 56/207 DS11910 Rev 5 STM32L451xx Pinouts and pin description 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 VDD VSS PE1 PE0 PB9 PB8 PH3-BOOT0 PB7 PB6 PB5 PB4 PB3 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 PC12 PC11 PC10 PA15 PA14 Figure 6. STM32L451Vx LQFP100 pinout(1) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 LQFP100 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 VDD VSS VDD PA13 PA12 PA11 PA10 PA9 PA8 PC9 PC8 PC7 PC6 PD15 PD14 PD13 PD12 PD11 PD10 PD9 PD8 PB15 PB14 PB13 PB12 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 PE2 PE3 PE4 PE5 PE6 VBAT PC13 PC14-OSC32_IN PC15-OSC32_OUT VSS VDD PH0-OSC_IN PH1-OSC_OUT NRST PC0 PC1 PC2 PC3 VSSA VREFVREF+ VDDA PA0 PA1 PA2 PA3 VSS VDD PA4 PA5 PA6 PA7 PC4 PC5 PB0 PB1 PB2 PE7 PE8 PE9 PE10 PE11 PE12 PE13 PE14 PE15 PB10 PB11 VSS VDD 4 Pinouts and pin description MSv40964V2 1. The above figure shows the package top view. DS11910 Rev 5 57/207 86 Pinouts and pin description STM32L451xx Figure 7. STM32L451Vx UFBGA100 ballout(1) 1 2 3 4 5 6 7 8 9 10 11 12 A PE3 PE1 PB8 PH3-BOOT0 PD7 PD5 PB4 PB3 PA15 PA14 PA13 PA12 B PE4 PE2 PB9 PB7 PB6 PD6 PD4 PD3 PD1 PC12 PC10 PA11 C PC13 PE5 PE0 VDD PB5 PD2 PD0 PC11 VDD PA10 D PC14OSC32_IN PE6 VSS PA9 PA8 PC9 E PC15OSC32_OUT VBAT VSS PC8 PC7 PC6 F PH0-OSC_IN VSS VSS VSS VDD VDD UFBGA100 G PH1OSC_OUT VDD H PC0 NRST VDD PD15 PD14 PD13 J VSSA PC1 PC2 PD12 PD11 PD10 K VREF- PC3 PA2 PA5 PC4 L VREF+ PA0 PA3 PA6 PC5 PB2 M VDDA PA1 PA4 PA7 PB0 PB1 PD9 PD8 PB15 PB14 PB13 PE8 PE10 PE12 PB10 PB11 PB12 PE7 PE9 PE11 PE13 PE14 PE15 MSv40962V2 1. The above figure shows the package top view. VDD VSS PB9 PB8 PH3-BOOT0 PB7 PB6 PB5 PB4 PB3 PD2 PC12 PC11 PC10 PA15 PA14 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 Figure 8. STM32L451Rx LQFP64 pinout(1) VBAT 1 48 VDD PC13 2 47 VSS PC14-OSC32_IN 3 46 PC15-OSC32_OUT 4 45 PA12 PA13 PH0-OSC_IN 5 44 PA11 PH1-OSC_OUT 6 43 PA10 NRST 7 42 PA9 PC0 8 41 PA8 PC1 9 40 PC9 PC2 10 39 PC8 PC3 11 38 PC7 VSSA/VREF- 12 37 PC6 VDDA/VREF+ 13 36 PB15 PA0 14 35 PB14 PA1 15 34 PB13 PA2 16 33 PB12 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 PA3 VSS VDD PA4 PA5 PA6 PA7 PC4 PC5 PB0 PB1 PB2 PB10 PB11 VSS VDD LQFP64 MSv40958V2 1. The above figure shows the package top view. 58/207 DS11910 Rev 5 STM32L451xx Pinouts and pin description Figure 9. STM32L451Rx UFBGA64 ballout(1) 1 2 3 4 5 6 7 8 A PC14OSC32_IN PC13 PB9 PB4 PB3 PA15 PA14 PA13 B PC15OSC32_OUT VBAT PB8 PH3-BOOT0 PD2 PC11 PC10 PA12 C PH0-OSC_IN VSS PB7 PB5 PC12 PA10 PA9 PA11 D PH1OSC_OUT VDD PB6 VSS VSS VSS PA8 PC9 E NRST PC1 PC0 VDD VDD VDD PC7 PC8 F VSSA/VREF- PC2 PA2 PA5 PB0 PC6 PB15 PB14 G PC3 PA0 PA3 PA6 PB1 PB2 PB10 PB13 H VDDA/VREF+ PA1 PA4 PA7 PC4 PC5 PB11 PB12 MSv40960V2 1. The above figure shows the package top view. Figure 10. STM32L451Rx WLCSP64 pinout(1) 1 2 3 4 5 6 7 8 A VDD PA15 PC12 PB4 PB7 PB8 VSS VDD B VSS VDD PC11 PB3 PB6 PH3-BOOT0 VBAT PC13 C PA10 PA13 PA14 PD2 PB5 PB9 PC15OSC32_OUT PC14OSC32_IN D PA9 PA11 PA12 PC10 PC1 PC2 PC0 PH0-OSC_IN E PC7 PC9 PA8 PC4 PA7 PA1 PC3 PH1OSC_OUT F PB15 PC6 PC8 PB1 PA5 PA3 VDDA/VREF+ NRST G PB14 PB13 PB12 PB2 PC5 PA4 PA2 VSSA/VREF- H VDD VSS PB11 PB10 PB0 PA6 VDD PA0 MSv40956V2 1. The above figure shows the package top view. DS11910 Rev 5 59/207 86 Pinouts and pin description STM32L451xx VDD VSS PB9 PB8 PH3/BOOT0 PB7 PB6 PB5 PB4 PB3 PA15 PA14 48 47 46 45 44 43 42 41 40 39 38 37 Figure 11. STM32L451Cx LQFP48 pinout(1) VBAT 1 36 VDD PC13 2 35 VSS PC14-OSC32_IN 3 34 PA13 PC15-OSC32_OUT 4 33 PA12 PH0-OSC_IN 5 32 PA11 PH1-OSC_OUT 6 31 PA10 NRST 7 30 PA9 VSSA/VREF- 8 29 PA8 VDDA/VREF+ 9 28 PB15 PA0 10 27 PB14 PA1 11 26 PB13 PA2 12 25 PB12 13 14 15 16 17 18 19 20 21 22 23 24 PA3 PA4 PA5 PA6 PA7 PB0 PB1 PB2 PB10 PB11 VSS VDD LQFP48 MSv39208V2 1. The above figure shows the package top view. VDD VSS PB9 PB8 PH3-BOOT0 PB7 PB6 PB5 PB4 PB3 PA15 PA14 48 47 46 45 44 43 42 41 40 39 38 37 Figure 12. STM32L451Cx UFQFPN48 pinout(1) VBAT 1 36 VDD PC13 2 35 VSS PC14-OSC32_IN 3 34 PA13 PC15-OSC32_OUT 4 33 PA12 PH0-OSC_IN 5 32 PA11 PH1-OSC_OUT 6 31 PA10 NRST 7 30 PA9 VSSA/VREF- 8 29 PA8 VDDA/VREF+ 9 28 PB15 PA0 10 27 PB14 PA1 11 26 PB13 PA2 12 25 PB12 13 14 15 16 17 18 19 20 21 22 23 24 PA3 PA4 PA5 PA6 PA7 PB0 PB1 PB2 PB10 PB11 VSS VDD UFQFPN48 MSv40954V2 1. The above figure shows the package top view. 60/207 DS11910 Rev 5 STM32L451xx Pinouts and pin description Table 15. Legend/abbreviations used in the pinout table Name Abbreviation Definition Unless otherwise specified in brackets below the pin name, the pin function during and after reset is the same as the actual pin name Pin name S Supply pin I Input only pin Pin type I/O Input / output pin FT 5 V tolerant I/O TT 3.6 V tolerant I/O RST Bidirectional reset pin with embedded weak pull-up resistor I/O structure Option for TT or FT I/Os _f (1) _a Notes I/O, Fm+ capable (2) I/O, with Analog switch function supplied by VDDA Unless otherwise specified by a note, all I/Os are set as analog inputs during and after reset. Alternate Functions selected through GPIOx_AFR registers functions Pin functions Additional Functions directly selected/enabled through peripheral registers functions 1. The related I/O structures in Table 16 are: FT_f, FT_fa. 2. The related I/O structures in Table 16 are: FT_a, FT_fa, TT_a. Table 16. STM32L451xx pin definitions Pin functions Alternate functions Additional functions - Notes I/O structure Pin type Pin name (function after reset) UFBGA100 LQFP100 UFBGA64 LQFP64 WLCSP64 LQFP48, UFQFPN48 Pin Number - - - - 1 B2 PE2 I/O FT - TRACECK, TIM3_ETR, TSC_G7_IO1, SAI1_MCLK_A, EVENTOUT - - - - 2 A1 PE3 I/O FT - TRACED0, TIM3_CH1, TSC_G7_IO2, SAI1_SD_B, EVENTOUT - - TRACED1, TIM3_CH2, DFSDM1_DATIN3, TSC_G7_IO3, SAI1_FS_A, EVENTOUT - - - - - 3 B1 PE4 I/O FT DS11910 Rev 5 61/207 86 Pinouts and pin description STM32L451xx Table 16. STM32L451xx pin definitions (continued) Pin functions Alternate functions Additional functions - Notes I/O structure Pin type Pin name (function after reset) UFBGA100 LQFP100 UFBGA64 LQFP64 WLCSP64 LQFP48, UFQFPN48 Pin Number - - - - 4 C2 PE5 I/O FT - TRACED2, TIM3_CH3, DFSDM1_CKIN3, TSC_G7_IO4, SAI1_SCK_A, EVENTOUT - - - - 5 D2 PE6 I/O FT - TRACED3, TIM3_CH4, SAI1_SD_A, EVENTOUT RTC_TAMP3, WKUP3 1 B7 1 B2 6 E2 VBAT S - - - - EVENTOUT RTC_TAMP1, RTC_TS, RTC_OUT, WKUP2 EVENTOUT OSC32_IN (2) EVENTOUT OSC32_OUT 2 3 B8 C8 2 3 A2 A1 7 8 C1 PC13 I/O FT D1 PC14OSC32_ IN (PC14) I/O FT I/O FT (1) (2) (1) (2) 4 C7 4 B1 9 E1 PC15OSC32_ OUT (PC15) - - - - 10 F2 VSS S - - - - - - - - 11 G2 VDD S - - - - 5 D8 5 C1 12 F1 PH0OSC_IN (PH0) I/O FT - EVENTOUT OSC_IN I/O FT - EVENTOUT OSC_OUT (1) 6 E8 6 D1 13 G1 PH1OSC_ OUT (PH1) 7 F8 7 E1 14 H2 NRST I/O RST - - - - D7 8 E3 15 H1 PC0 I/O FT_fa - LPTIM1_IN1, I2C4_SCL, I2C3_SCL, LPUART1_RX, LPTIM2_IN1, EVENTOUT ADC1_IN1 - D5 9 E2 16 J2 PC1 I/O FT_fa - TRACED0, LPTIM1_OUT, I2C4_SDA, I2C3_SDA, LPUART1_TX, EVENTOUT ADC1_IN2 - D6 10 F2 17 J3 PC2 I/O FT_a - LPTIM1_IN2, SPI2_MISO, DFSDM1_CKOUT, EVENTOUT ADC1_IN3 62/207 DS11910 Rev 5 STM32L451xx Pinouts and pin description Table 16. STM32L451xx pin definitions (continued) Pin functions Pin type I/O structure Notes Pin name (function after reset) UFBGA100 UFBGA64 LQFP64 E7 11 G1 LQFP100 - WLCSP64 LQFP48, UFQFPN48 Pin Number 18 K2 PC3 I/O FT_a - LPTIM1_ETR, SPI2_MOSI, SAI1_SD_A, LPTIM2_ETR, EVENTOUT ADC1_IN4 Alternate functions Additional functions - - - - 19 J1 VSSA S - - - - - - - - 20 K1 VREF- S - - - - - - VSSA/ VREF- S - - - - 8 G8 12 F1 - - - - 21 L1 VREF+ S - - - VREFBUF_OUT - - - - 22 M1 VDDA S - - - - - - VDDA/ VREF+ S - - - - 9 F7 13 H1 10 H8 14 G2 11 E6 15 H2 12 G7 16 F3 23 24 25 L2 M2 K3 PA0 PA1 PA2 I/O I/O I/O FT_a FT_a FT_a - TIM2_CH1, USART2_CTS, OPAMP1_VINP, UART4_TX, COMP1_OUT, COMP1_INM, SAI1_EXTCLK, TIM2_ETR, ADC1_IN5, RTC_TAMP2, EVENTOUT WKUP1 - TIM2_CH2, I2C1_SMBA, SPI1_SCK, USART2_RTS_DE, UART4_RX, TIM15_CH1N, EVENTOUT OPAMP1_VINM, COMP1_INP, ADC1_IN6 - TIM2_CH3, USART2_TX, LPUART1_TX, QUADSPI_BK1_NCS, COMP2_OUT, TIM15_CH1, EVENTOUT COMP2_INM, ADC1_IN7, WKUP4,LSCO OPAMP1_VOUT, COMP2_INP, ADC1_IN8 26 L3 PA3 I/O TT_a - TIM2_CH4, USART2_RX, LPUART1_RX, QUADSPI_CLK, SAI1_MCLK_A, TIM15_CH2, EVENTOUT 18 C2 27 E3 VSS S - - - - H7 19 D2 28 H3 VDD S - - - - 14 G6 20 H3 29 M3 PA4 I/O TT_a - 13 F6 17 G3 - - SPI1_NSS, SPI3_NSS, COMP1_INM, USART2_CK, SAI1_FS_B, COMP2_INM, LPTIM2_OUT, EVENTOUT ADC1_IN9, DAC1_OUT1 DS11910 Rev 5 63/207 86 Pinouts and pin description STM32L451xx Table 16. STM32L451xx pin definitions (continued) Pin functions 15 F5 21 F4 16 H6 22 G4 17 E5 23 H4 30 31 K4 L4 PA5 PA6 I/O I/O TT_a FT_a Alternate functions Additional functions - TIM2_CH1, TIM2_ETR, SPI1_SCK, DFSDM1_CKOUT, LPTIM2_ETR, EVENTOUT COMP1_INM, COMP2_INM, ADC1_IN10 - TIM1_BKIN, TIM3_CH1, SPI1_MISO, COMP1_OUT, USART3_CTS, LPUART1_CTS, QUADSPI_BK1_IO3, TIM1_BKIN_COMP2, TIM16_CH1, EVENTOUT ADC1_IN11 ADC1_IN12 Notes I/O structure Pin type Pin name (function after reset) UFBGA100 LQFP100 UFBGA64 LQFP64 WLCSP64 LQFP48, UFQFPN48 Pin Number 32 M4 PA7 I/O FT_fa - TIM1_CH1N, TIM3_CH2, I2C3_SCL, SPI1_MOSI, DFSDM1_DATIN0, QUADSPI_BK1_IO2, COMP2_OUT, EVENTOUT - E4 24 H5 33 K5 PC4 I/O FT_a - USART3_TX, EVENTOUT COMP1_INM, ADC1_IN13 - G5 25 H6 34 L5 PC5 I/O FT_a - USART3_RX, EVENTOUT COMP1_INP, ADC1_IN14, WKUP5 - TIM1_CH2N, TIM3_CH3, SPI1_NSS, DFSDM1_CKIN0, USART3_CK, QUADSPI_BK1_IO1, COMP1_OUT, SAI1_EXTCLK, EVENTOUT ADC1_IN15 - TIM1_CH3N, TIM3_CH4, DFSDM1_DATIN0, USART3_RTS_DE, LPUART1_RTS_DE, QUADSPI_BK1_IO0, LPTIM2_IN1, EVENTOUT COMP1_INM, ADC1_IN16 COMP1_INP - 18 H5 26 F5 19 F4 27 G5 20 G4 28 G6 - - 64/207 - - 35 36 M5 M6 PB0 PB1 I/O I/O FT_a FT_a 37 L6 PB2 I/O FT_a - RTC_OUT, LPTIM1_OUT, I2C3_SMBA, DFSDM1_CKIN0, EVENTOUT 38 M7 PE7 I/O FT - TIM1_ETR, DFSDM1_DATIN2, SAI1_SD_B, EVENTOUT DS11910 Rev 5 STM32L451xx Pinouts and pin description Table 16. STM32L451xx pin definitions (continued) Pin functions WLCSP64 LQFP64 UFBGA64 LQFP100 UFBGA100 Pin type I/O structure Notes - - - - 39 L7 PE8 I/O FT - TIM1_CH1N, DFSDM1_CKIN2, SAI1_SCK_B, EVENTOUT - - - - - 40 M8 PE9 I/O FT - TIM1_CH1, DFSDM1_CKOUT, SAI1_FS_B, EVENTOUT - - Pin name (function after reset) LQFP48, UFQFPN48 Pin Number Alternate functions Additional functions - - - - 41 L8 PE10 I/O FT - TIM1_CH2N, TSC_G5_IO1, QUADSPI_CLK, SAI1_MCLK_B, EVENTOUT - - - - 42 M9 PE11 I/O FT - TIM1_CH2, TSC_G5_IO2, QUADSPI_BK1_NCS, EVENTOUT - - TIM1_CH3N, SPI1_NSS, TSC_G5_IO3, QUADSPI_BK1_IO0, EVENTOUT - - TIM1_CH3, SPI1_SCK, TSC_G5_IO4, QUADSPI_BK1_IO1, EVENTOUT - - TIM1_CH4, TIM1_BKIN2, TIM1_BKIN2_COMP2, SPI1_MISO, QUADSPI_BK1_IO2, EVENTOUT - - TIM1_BKIN, TIM1_BKIN_COMP1, SPI1_MOSI, QUADSPI_BK1_IO3, EVENTOUT - - TIM2_CH3, I2C4_SCL, I2C2_SCL, SPI2_SCK, USART3_TX, LPUART1_RX, TSC_SYNC, QUADSPI_CLK, COMP1_OUT, SAI1_SCK_A, EVENTOUT - - - - - - - - - - - - - - - - - 21 H4 29 G7 43 L9 44 M10 45 M11 46 M12 47 L10 PE12 PE13 PE14 PE15 PB10 I/O I/O I/O I/O I/O FT FT FT FT FT_f DS11910 Rev 5 65/207 86 Pinouts and pin description STM32L451xx Table 16. STM32L451xx pin definitions (continued) Pin functions Alternate functions Additional functions - Notes I/O structure Pin type Pin name (function after reset) UFBGA100 LQFP100 UFBGA64 LQFP64 WLCSP64 LQFP48, UFQFPN48 Pin Number 22 H3 30 H7 48 L11 PB11 I/O FT_f - TIM2_CH4, I2C4_SDA, I2C2_SDA, USART3_RX, LPUART1_TX, QUADSPI_BK1_NCS, COMP2_OUT, EVENTOUT 23 H2 31 D6 49 F12 VSS S - - - - 24 H1 32 E6 50 G12 VDD S - - - - - TIM1_BKIN, TIM1_BKIN_COMP2, I2C2_SMBA, SPI2_NSS, DFSDM1_DATIN1, USART3_CK, LPUART1_RTS_DE, TSC_G1_IO1, CAN1_RX, SAI1_FS_A, TIM15_BKIN, EVENTOUT - - TIM1_CH1N, I2C2_SCL, SPI2_SCK, DFSDM1_CKIN1, USART3_CTS, LPUART1_CTS, TSC_G1_IO2, CAN1_TX, SAI1_SCK_A, TIM15_CH1N, EVENTOUT - - TIM1_CH2N, I2C2_SDA, SPI2_MISO, DFSDM1_DATIN2, USART3_RTS_DE, TSC_G1_IO3, SAI1_MCLK_A, TIM15_CH1, EVENTOUT - - 25 G3 33 H8 26 G2 34 G8 27 G1 35 F8 28 F1 36 F7 51 52 53 L12 K12 K11 PB12 PB13 PB14 I/O I/O I/O FT FT_f FT_f 54 K10 PB15 I/O FT - RTC_REFIN, TIM1_CH3N, SPI2_MOSI, DFSDM1_CKIN2, TSC_G1_IO4, SAI1_SD_A, TIM15_CH2, EVENTOUT - - - - 55 K9 PD8 I/O FT - USART3_TX, EVENTOUT - - - - - 56 K8 PD9 I/O FT - USART3_RX, EVENTOUT - - - - - 57 J12 PD10 I/O FT - USART3_CK, TSC_G6_IO1, EVENTOUT - 66/207 DS11910 Rev 5 STM32L451xx Pinouts and pin description Table 16. STM32L451xx pin definitions (continued) Pin functions - - - - 58 J11 PD11 I/O FT Alternate functions Additional functions - I2C4_SMBA, USART3_CTS, TSC_G6_IO2, LPTIM2_ETR, EVENTOUT - - Notes I/O structure Pin type Pin name (function after reset) UFBGA100 LQFP100 UFBGA64 LQFP64 WLCSP64 LQFP48, UFQFPN48 Pin Number - - - - 59 J10 PD12 I/O FT - I2C4_SCL, USART3_RTS_DE, TSC_G6_IO3, LPTIM2_IN1, EVENTOUT - - - - 60 H12 PD13 I/O FT - I2C4_SDA, TSC_G6_IO4, LPTIM2_OUT, EVENTOUT - - - - - 61 H11 PD14 I/O FT - EVENTOUT - - - - - 62 H10 PD15 I/O FT - EVENTOUT - - TIM3_CH1, DFSDM1_CKIN3, TSC_G4_IO1, SDMMC1_D6, EVENTOUT - - - F2 37 F6 63 E12 PC6 I/O FT - E1 38 E7 64 E11 PC7 I/O FT - TIM3_CH2, DFSDM1_DATIN3, TSC_G4_IO2, SDMMC1_D7, EVENTOUT - F3 39 E8 65 E10 PC8 I/O FT - TIM3_CH3, TSC_G4_IO3, SDMMC1_D0, EVENTOUT - - E2 40 D8 66 D12 PC9 I/O FT - TIM3_CH4, TSC_G4_IO4, SDMMC1_D1, EVENTOUT - - MCO, TIM1_CH1, DFSDM1_CKIN1, USART1_CK, SAI1_SCK_A, LPTIM2_OUT, EVENTOUT - - - 29 E3 41 D7 67 D11 PA8 I/O FT 30 D1 42 C7 68 D10 PA9 I/O FT_f - TIM1_CH2, I2C1_SCL, DFSDM1_DATIN1, USART1_TX, SAI1_FS_A, TIM15_BKIN, EVENTOUT 31 C1 43 C6 69 C12 PA10 I/O FT_f - TIM1_CH3, I2C1_SDA, USART1_RX, SAI1_SD_A, EVENTOUT DS11910 Rev 5 67/207 86 Pinouts and pin description STM32L451xx Table 16. STM32L451xx pin definitions (continued) Pin functions Alternate functions Additional functions - Notes I/O structure Pin type Pin name (function after reset) UFBGA100 LQFP100 UFBGA64 LQFP64 WLCSP64 LQFP48, UFQFPN48 Pin Number 32 D2 44 C8 70 B12 PA11 I/O FT - TIM1_CH4, TIM1_BKIN2, SPI1_MISO, COMP1_OUT, USART1_CTS, CAN1_RX, TIM1_BKIN2_COMP1, EVENTOUT 33 D3 45 B8 71 A12 PA12 I/O FT_f - TIM1_ETR, SPI1_MOSI, USART1_RTS_DE, CAN1_TX, EVENTOUT - 34 C2 46 A8 72 A11 PA13 (JTMS/ SWDIO) I/O FT (3) JTMS/SWDAT, IR_OUT, SAI1_SD_B, EVENTOUT - 35 B1 47 D5 - - VSS S - - - - 36 A1 48 E5 73 C11 VDD S - - - - - - - - 74 F11 VSS S - - - - - B2 - - 75 G11 VDD S - - - - A10 PA14 (JTCK/ SWCLK) 37 C3 49 A7 38 A2 50 A6 76 77 A9 PA15 (JTDI) I/O I/O FT JTCK/SWCLK, LPTIM1_OUT, I2C1_SMBA, (3) I2C4_SMBA, SAI1_FS_B, EVENTOUT - FT JTDI, TIM2_CH1, TIM2_ETR, USART2_RX, SPI1_NSS, SPI3_NSS, (3) USART3_RTS_DE, UART4_RTS_DE, TSC_G3_IO1, EVENTOUT - - - D4 51 B7 78 B11 PC10 I/O FT - TRACED1, SPI3_SCK, USART3_TX, UART4_TX, TSC_G3_IO2, SDMMC1_D2, EVENTOUT - B3 52 B6 79 C10 PC11 I/O FT - SPI3_MISO, USART3_RX, UART4_RX, TSC_G3_IO3, SDMMC1_D3, EVENTOUT - - - - - A3 53 C5 - 68/207 - - 80 B10 PC12 I/O FT - TRACED3, SPI3_MOSI, USART3_CK, TSC_G3_IO4, SDMMC1_CK, EVENTOUT 81 C9 PD0 I/O FT - SPI2_NSS, CAN1_RX, EVENTOUT DS11910 Rev 5 STM32L451xx Pinouts and pin description Table 16. STM32L451xx pin definitions (continued) Pin functions LQFP100 UFBGA100 - 82 B9 - - C4 54 B5 - - - 83 84 C8 B8 PD1 PD2 PD3 Notes UFBGA64 - I/O structure LQFP64 - Pin type WLCSP64 - Pin name (function after reset) LQFP48, UFQFPN48 Pin Number I/O FT - I/O I/O FT FT Alternate functions Additional functions SPI2_SCK, CAN1_TX, EVENTOUT - - TRACED2, TIM3_ETR, USART3_RTS_DE, TSC_SYNC, SDMMC1_CMD, EVENTOUT - - SPI2_MISO, DFSDM1_DATIN0, USART2_CTS, QUADSPI_BK2_NCS, EVENTOUT - - - - - - 85 B7 PD4 I/O FT - SPI2_MOSI, DFSDM1_CKIN0, USART2_RTS_DE, QUADSPI_BK2_IO0, EVENTOUT - - - - 86 A6 PD5 I/O FT - USART2_TX, QUADSPI_BK2_IO1, EVENTOUT - - DFSDM1_DATIN1, USART2_RX, QUADSPI_BK2_IO2, SAI1_SD_A, EVENTOUT - - DFSDM1_CKIN1, USART2_CK, QUADSPI_BK2_IO3, EVENTOUT - - - - - - - - - 39 B4 55 A5 40 A4 56 A4 87 88 89 90 B6 PD6 A5 PD7 A8 PB3 (JTDO/ TRACE SWO) A7 PB4 (NJTRST) I/O I/O I/O I/O FT FT JTDO/TRACESWO, TIM2_CH2, SPI1_SCK, SPI3_SCK, FT_a (3) USART1_RTS_DE, SAI1_SCK_B, EVENTOUT FT_fa (3) NJTRST, TIM3_CH1, I2C3_SDA, SPI1_MISO, SPI3_MISO, USART1_CTS, TSC_G2_IO1, SAI1_MCLK_B, EVENTOUT DS11910 Rev 5 COMP2_INM COMP2_INP 69/207 86 Pinouts and pin description STM32L451xx Table 16. STM32L451xx pin definitions (continued) Pin functions 41 C5 57 C4 42 B5 58 D3 91 92 C5 B5 PB5 PB6 I/O I/O FT FT_fa Alternate functions Additional functions - LPTIM1_IN1, TIM3_CH2, CAN1_RX, I2C1_SMBA, SPI1_MOSI, SPI3_MOSI, USART1_CK, TSC_G2_IO2, COMP2_OUT, SAI1_SD_B, TIM16_BKIN, EVENTOUT - - LPTIM1_ETR, I2C1_SCL, I2C4_SCL, USART1_TX, CAN1_TX, TSC_G2_IO3, SAI1_FS_B, TIM16_CH1N, EVENTOUT COMP2_INP COMP2_INM, PVD_IN Notes I/O structure Pin type Pin name (function after reset) UFBGA100 LQFP100 UFBGA64 LQFP64 WLCSP64 LQFP48, UFQFPN48 Pin Number 43 A5 59 C3 93 B4 PB7 I/O FT_fa - LPTIM1_IN2, I2C1_SDA, I2C4_SDA, USART1_RX, UART4_CTS, TSC_G2_IO4, EVENTOUT 44 B6 60 B4 94 A4 PH3BOOT0 (BOOT0) I/O - - EVENTOUT BOOT0 - I2C1_SCL, CAN1_RX, SDMMC1_D4, SAI1_MCLK_A, TIM16_CH1, EVENTOUT - - 45 A6 61 B3 46 C6 62 A3 95 A3 PB8 I/O FT_f 96 B3 PB9 I/O FT_f - IR_OUT, I2C1_SDA, SPI2_NSS, CAN1_TX, SDMMC1_D5, SAI1_FS_A, EVENTOUT - - - - 97 C3 PE0 I/O FT - TIM16_CH1, EVENTOUT - - - - - 98 A2 PE1 I/O FT - EVENTOUT - 99 D3 VSS S - - - - 48 A8 64 E4 100 C4 VDD S - - - - 47 A7 63 D4 1. PC13, PC14 and PC15 are supplied through the power switch. Since the switch only sinks a limited amount of current (3 mA), the use of GPIOs PC13 to PC15 in output mode is limited: - The speed should not exceed 2 MHz with a maximum load of 30 pF - These GPIOs must not be used as current sources (e.g. to drive an LED). 2. After a Backup domain power-up, PC13, PC14 and PC15 operate as GPIOs. Their function then depends on the content of the RTC registers which are not reset by the system reset. For details on how to manage these GPIOs, refer to the Backup domain and RTC register descriptions in the RM0394 reference manual. 3. After reset, these pins are configured as JTAG/SW debug alternate functions, and the internal pull-up on PA15, PA13, PB4 pins and the internal pull-down on PA14 pin are activated. 70/207 DS11910 Rev 5 AF1 AF2 AF3 AF4 AF5 AF6 AF7 SYS_AF TIM1/TIM2 LPTIM1 I2C4/TIM1/ TIM2/TIM3 I2C4/USART2/ CAN1/TIM1 I2C1/I2C2/ I2C3/I2C4 SPI1/SPI2/I2C4 SPI3/DFSDM/ COMP1 USART1/ USART2/ USART3 PA0 - TIM2_CH1 - - - - - USART2_CTS PA1 - TIM2_CH2 - - I2C1_SMBA SPI1_SCK - USART2_RTS_ DE PA2 - TIM2_CH3 - - - - - USART2_TX PA3 - TIM2_CH4 - - - - - USART2_RX PA4 - - - - - SPI1_NSS SPI3_NSS USART2_CK PA5 - TIM2_CH1 TIM2_ETR - - SPI1_SCK DFSDM1_ CKOUT - PA6 - TIM1_BKIN TIM3_CH1 - - SPI1_MISO COMP1_OUT USART3_CTS PA7 - TIM1_CH1N TIM3_CH2 - I2C3_SCL SPI1_MOSI DFSDM1_ DATIN0 - PA8 MCO TIM1_CH1 - - - - DFSDM1_ CKIN1 USART1_CK PA9 - TIM1_CH2 - - I2C1_SCL - DFSDM1_ DATIN1 USART1_TX PA10 - TIM1_CH3 - - I2C1_SDA - - USART1_RX PA11 - TIM1_CH4 TIM1_BKIN2 - - SPI1_MISO COMP1_OUT USART1_CTS PA12 - TIM1_ETR - - - SPI1_MOSI - USART1_RTS_ DE PA13 JTMS/SWDAT IR_OUT - - - - - - PA14 JTCK/SWCLK LPTIM1_OUT - - I2C1_SMBA I2C4_SMBA - - PA15 JTDI TIM2_CH1 TIM2_ETR USART2_RX - SPI1_NSS SPI3_NSS USART3_RTS_ DE Port DS11910 Rev 5 Port A 71/207 Pinouts and pin description AF0 STM32L451xx Table 17. Alternate function AF0 to AF7(1) AF1 AF2 AF3 AF4 AF5 AF6 AF7 SYS_AF TIM1/TIM2 LPTIM1 I2C4/TIM1/ TIM2/TIM3 I2C4/USART2/ CAN1/TIM1 I2C1/I2C2/ I2C3/I2C4 SPI1/SPI2/I2C4 SPI3/DFSDM/ COMP1 USART1/ USART2/ USART3 PB0 - TIM1_CH2N TIM3_CH3 - - SPI1_NSS DFSDM1_ CKIN0 USART3_CK PB1 - TIM1_CH3N TIM3_CH4 - - - DFSDM1_ DATIN0 USART3_RTS_ DE PB2 RTC_OUT LPTIM1_OUT - - I2C3_SMBA - DFSDM1_ CKIN0 - PB3 JTDO/ TRACESWO TIM2_CH2 - - - SPI1_SCK SPI3_SCK USART1_RTS_ DE PB4 NJTRST - TIM3_CH1 - I2C3_SDA SPI1_MISO SPI3_MISO USART1_CTS PB5 - LPTIM1_IN1 TIM3_CH2 CAN1_RX I2C1_SMBA SPI1_MOSI SPI3_MOSI USART1_CK PB6 - LPTIM1_ETR - - I2C1_SCL I2C4_SCL - USART1_TX PB7 - LPTIM1_IN2 - - I2C1_SDA I2C4_SDA - USART1_RX PB8 - - - - I2C1_SCL - - - PB9 - IR_OUT - - I2C1_SDA SPI2_NSS - - PB10 - TIM2_CH3 - I2C4_SCL I2C2_SCL SPI2_SCK - USART3_TX PB11 - TIM2_CH4 - I2C4_SDA I2C2_SDA - - USART3_RX PB12 - TIM1_BKIN - TIM1_BKIN_C OMP2 I2C2_SMBA SPI2_NSS DFSDM1_ DATIN1 USART3_CK PB13 - TIM1_CH1N - - I2C2_SCL SPI2_SCK DFSDM1_ CKIN1 USART3_CTS PB14 - TIM1_CH2N - - I2C2_SDA SPI2_MISO DFSDM1_ DATIN2 USART3_RTS_ DE PB15 RTC_REFIN TIM1_CH3N - - - SPI2_MOSI DFSDM1_ CKIN2 - Port DS11910 Rev 5 Port B STM32L451xx AF0 Pinouts and pin description 72/207 Table 17. Alternate function AF0 to AF7(1) (continued) AF1 AF2 AF3 AF4 AF5 AF6 AF7 SYS_AF TIM1/TIM2 LPTIM1 I2C4/TIM1/ TIM2/TIM3 I2C4/USART2/ CAN1/TIM1 I2C1/I2C2/ I2C3/I2C4 SPI1/SPI2/I2C4 SPI3/DFSDM/ COMP1 USART1/ USART2/ USART3 PC0 - LPTIM1_IN1 I2C4_SCL - I2C3_SCL - - - PC1 TRACED0 LPTIM1_OUT I2C4_SDA - I2C3_SDA - - - PC2 - LPTIM1_IN2 - - - SPI2_MISO DFSDM1_ CKOUT - PC3 - LPTIM1_ETR - - - SPI2_MOSI - - PC4 - - - - - - - USART3_TX PC5 - - - - - - - USART3_RX PC6 - - TIM3_CH1 - - - DFSDM1_ CKIN3 - PC7 - - TIM3_CH2 - - - DFSDM1_ DATIN3 - PC8 - - TIM3_CH3 - - - - - PC9 - - TIM3_CH4 - - - - - PC10 TRACED1 - - - - - SPI3_SCK USART3_TX PC11 - - - - - - SPI3_MISO USART3_RX PC12 TRACED3 - - - - - SPI3_MOSI USART3_CK PC13 - - - - - - - - PC14 - - - - - - - - PC15 - - - - - - - - Port DS11910 Rev 5 Port C 73/207 Pinouts and pin description AF0 STM32L451xx Table 17. Alternate function AF0 to AF7(1) (continued) AF1 AF2 AF3 AF4 AF5 AF6 AF7 SYS_AF TIM1/TIM2 LPTIM1 I2C4/TIM1/ TIM2/TIM3 I2C4/USART2/ CAN1/TIM1 I2C1/I2C2/ I2C3/I2C4 SPI1/SPI2/I2C4 SPI3/DFSDM/ COMP1 USART1/ USART2/ USART3 PD0 - - - - - SPI2_NSS - - PD1 - - - - - SPI2_SCK - - PD2 TRACED2 - TIM3_ETR - - - - USART3_RTS_ DE PD3 - - - - - SPI2_MISO DFSDM1_ DATIN0 USART2_CTS PD4 - - - - - SPI2_MOSI DFSDM1_ CKIN0 USART2_RTS_ DE PD5 - - - - - - - USART2_TX PD6 - - - - - - DFSDM1_ DATIN1 USART2_RX PD7 - - - - - - DFSDM1_ CKIN1 USART2_CK PD8 - - - - - - - USART3_TX PD9 - - - - - - - USART3_RX PD10 - - - - - - - USART3_CK PD11 - - - - I2C4_SMBA - - USART3_CTS PD12 - - - - I2C4_SCL - - USART3_RTS_ DE PD13 - - - - I2C4_SDA - - - PD14 - - - - - - - - PD15 - - - - - - - - Port DS11910 Rev 5 Port D STM32L451xx AF0 Pinouts and pin description 74/207 Table 17. Alternate function AF0 to AF7(1) (continued) AF1 AF2 AF3 AF4 AF5 AF6 AF7 SYS_AF TIM1/TIM2 LPTIM1 I2C4/TIM1/ TIM2/TIM3 I2C4/USART2/ CAN1/TIM1 I2C1/I2C2/ I2C3/I2C4 SPI1/SPI2/I2C4 SPI3/DFSDM/ COMP1 USART1/ USART2/ USART3 PE0 - - - - - - - - PE1 - - - - - - - - PE2 TRACECK - TIM3_ETR - - - - - PE3 TRACED0 - TIM3_CH1 - - - - - PE4 TRACED1 - TIM3_CH2 - - - DFSDM1_ DATIN3 - PE5 TRACED2 - TIM3_CH3 - - - DFSDM1_ CKIN3 - PE6 TRACED3 - TIM3_CH4 - - - - - PE7 - TIM1_ETR - - - - DFSDM1_ DATIN2 - PE8 - TIM1_CH1N - - - - DFSDM1_ CKIN2 - PE9 - TIM1_CH1 - - - - DFSDM1_ CKOUT - PE10 - TIM1_CH2N - - - - - - PE11 - TIM1_CH2 - - - - - - PE12 - TIM1_CH3N - - - SPI1_NSS - - PE13 - TIM1_CH3 - - - SPI1_SCK - - PE14 - TIM1_CH4 TIM1_BKIN2 TIM1_BKIN2_ COMP2 - SPI1_MISO - - PE15 - TIM1_BKIN - TIM1_BKIN_ COMP1 - SPI1_MOSI - - Port DS11910 Rev 5 Port E 75/207 Pinouts and pin description AF0 STM32L451xx Table 17. Alternate function AF0 to AF7(1) (continued) AF0 AF1 AF2 AF3 AF4 AF5 AF6 AF7 SYS_AF TIM1/TIM2 LPTIM1 I2C4/TIM1/ TIM2/TIM3 I2C4/USART2/ CAN1/TIM1 I2C1/I2C2/ I2C3/I2C4 SPI1/SPI2/I2C4 SPI3/DFSDM/ COMP1 USART1/ USART2/ USART3 PH0 - - - - - - - - PH1 - - - - - - - - PH3 - - - - - - - - Port Port H 1. Refer to Table 18 for AF8 to AF15. Pinouts and pin description 76/207 Table 17. Alternate function AF0 to AF7(1) (continued) DS11910 Rev 5 STM32L451xx AF9 AF10 AF11 AF12 AF13 AF14 AF15 UART4/ LPUART1/ CAN1 CAN1/TSC CAN1/ QUADSPI - SDMMC1/ COMP1/ COMP2 SAI1 TIM2/TIM15/ TIM16/LPTIM2 EVENTOUT PA0 UART4_TX - - - COMP1_OUT SAI1_EXTCLK TIM2_ETR EVENTOUT PA1 UART4_RX - - - - - TIM15_CH1N EVENTOUT PA2 LPUART1_TX - QUADSPI_ BK1_NCS - COMP2_OUT - TIM15_CH1 EVENTOUT PA3 LPUART1_RX - QUADSPI_CLK - - SAI1_MCLK_A TIM15_CH2 EVENTOUT PA4 - - - - - SAI1_FS_B LPTIM2_OUT EVENTOUT PA5 - - - - - - LPTIM2_ETR EVENTOUT PA6 LPUART1_CTS - QUADSPI_ BK1_IO3 - TIM1_BKIN_ COMP2 - TIM16_CH1 EVENTOUT PA7 - - QUADSPI_ BK1_IO2 - COMP2_OUT - - EVENTOUT PA8 - - - - - SAI1_SCK_A LPTIM2_OUT EVENTOUT PA9 - - - - - SAI1_FS_A TIM15_BKIN EVENTOUT PA10 - - - - - SAI1_SD_A - EVENTOUT PA11 - CAN1_RX - - TIM1_BKIN2_ COMP1 - - EVENTOUT PA12 - CAN1_TX - - - - - EVENTOUT PA13 - - - - - SAI1_SD_B - EVENTOUT PA14 - - - - - SAI1_FS_B - EVENTOUT PA15 UART4_RTS_ DE TSC_G3_IO1 - - - - - EVENTOUT Port DS11910 Rev 5 Port A 77/207 Pinouts and pin description AF8 STM32L451xx Table 18. Alternate function AF8 to AF15(1) AF8 AF9 AF10 AF11 AF12 AF13 AF14 AF15 UART4/ LPUART1/ CAN1 CAN1/TSC CAN1/ QUADSPI - SDMMC1/ COMP1/ COMP2 SAI1 TIM2/TIM15/ TIM16/LPTIM2 EVENTOUT PB0 - - QUADSPI_ BK1_IO1 - COMP1_OUT SAI1_EXTCLK - EVENTOUT PB1 LPUART1_RTS _DE - QUADSPI_ BK1_IO0 - - - LPTIM2_IN1 EVENTOUT PB2 - - - - - - - EVENTOUT PB3 - - - - - SAI1_SCK_B - EVENTOUT PB4 - TSC_G2_IO1 - - - SAI1_MCLK_B - EVENTOUT PB5 - TSC_G2_IO2 - - COMP2_OUT SAI1_SD_B TIM16_BKIN EVENTOUT PB6 CAN1_TX TSC_G2_IO3 - - - SAI1_FS_B TIM16_CH1N EVENTOUT PB7 UART4_CTS TSC_G2_IO4 - - - - - EVENTOUT PB8 - CAN1_RX - - SDMMC1_D4 SAI1_MCLK_A TIM16_CH1 EVENTOUT PB9 - CAN1_TX - - SDMMC1_D5 SAI1_FS_A - EVENTOUT PB10 LPUART1_RX TSC_SYNC QUADSPI_CLK - COMP1_OUT SAI1_SCK_A - EVENTOUT PB11 LPUART1_TX - QUADSPI_ BK1_NCS - COMP2_OUT - - EVENTOUT PB12 LPUART1_RTS _DE TSC_G1_IO1 CAN1_RX - - SAI1_FS_A TIM15_BKIN EVENTOUT PB13 LPUART1_CTS TSC_G1_IO2 CAN1_TX - - SAI1_SCK_A TIM15_CH1N EVENTOUT PB14 - TSC_G1_IO3 - - - SAI1_MCLK_A TIM15_CH1 EVENTOUT PB15 - TSC_G1_IO4 - - - SAI1_SD_A TIM15_CH2 EVENTOUT Port DS11910 Rev 5 Port B Pinouts and pin description 78/207 Table 18. Alternate function AF8 to AF15(1) (continued) STM32L451xx AF9 AF10 AF11 AF12 AF13 AF14 AF15 UART4/ LPUART1/ CAN1 CAN1/TSC CAN1/ QUADSPI - SDMMC1/ COMP1/ COMP2 SAI1 TIM2/TIM15/ TIM16/LPTIM2 EVENTOUT PC0 LPUART1_RX - - - - - LPTIM2_IN1 EVENTOUT PC1 LPUART1_TX - - - - - - EVENTOUT PC2 - - - - - - - EVENTOUT PC3 - - - - - SAI1_SD_A LPTIM2_ETR EVENTOUT PC4 - - - - - - - EVENTOUT PC5 - - - - - - - EVENTOUT PC6 - TSC_G4_IO1 - - SDMMC1_D6 - - EVENTOUT PC7 - TSC_G4_IO2 - - SDMMC1_D7 - - EVENTOUT PC8 - TSC_G4_IO3 - - SDMMC1_D0 - - EVENTOUT PC9 - TSC_G4_IO4 - - SDMMC1_D1 - - EVENTOUT PC10 UART4_TX TSC_G3_IO2 - - SDMMC1_D2 - - EVENTOUT PC11 UART4_RX TSC_G3_IO3 - - SDMMC1_D3 - - EVENTOUT PC12 - TSC_G3_IO4 - - SDMMC1_CK - - EVENTOUT PC13 - - - - - - - EVENTOUT PC14 - - - - - - - EVENTOUT PC15 - - - - - - - EVENTOUT Port DS11910 Rev 5 Port C 79/207 Pinouts and pin description AF8 STM32L451xx Table 18. Alternate function AF8 to AF15(1) (continued) AF9 AF10 AF11 AF12 AF13 AF14 AF15 UART4/ LPUART1/ CAN1 CAN1/TSC CAN1/ QUADSPI - SDMMC1/ COMP1/ COMP2 SAI1 TIM2/TIM15/ TIM16/LPTIM2 EVENTOUT PD0 - CAN1_RX - - - - - EVENTOUT PD1 - CAN1_TX - - - - - EVENTOUT PD2 - TSC_SYNC - - SDMMC1_ CMD - - EVENTOUT PD3 - - QUADSPI_ BK2_NCS - - - - EVENTOUT PD4 - - QUADSPI_ BK2_IO0 - - - - EVENTOUT PD5 - - QUADSPI_ BK2_IO1 - - - - EVENTOUT PD6 - - QUADSPI_ BK2_IO2 - - SAI1_SD_A - EVENTOUT PD7 - - QUADSPI_ BK2_IO3 - - - - EVENTOUT PD8 - - - - - - - EVENTOUT PD9 - - - - - - - EVENTOUT PD10 - TSC_G6_IO1 - - - - - EVENTOUT PD11 - TSC_G6_IO2 - - - - LPTIM2_ETR EVENTOUT PD12 - TSC_G6_IO3 - - - - LPTIM2_IN1 EVENTOUT PD13 - TSC_G6_IO4 - - - - LPTIM2_OUT EVENTOUT PD14 - - - - - - - EVENTOUT PD15 - - - - - - - EVENTOUT Port DS11910 Rev 5 Port D STM32L451xx AF8 Pinouts and pin description 80/207 Table 18. Alternate function AF8 to AF15(1) (continued) AF9 AF10 AF11 AF12 AF13 AF14 AF15 UART4/ LPUART1/ CAN1 CAN1/TSC CAN1/ QUADSPI - SDMMC1/ COMP1/ COMP2 SAI1 TIM2/TIM15/ TIM16/LPTIM2 EVENTOUT PE0 - - - - - - TIM16_CH1 EVENTOUT PE1 - - - - - - - EVENTOUT PE2 - TSC_G7_IO1 - - - SAI1_MCLK_A - EVENTOUT PE3 - TSC_G7_IO2 - - - SAI1_SD_B - EVENTOUT PE4 - TSC_G7_IO3 - - - SAI1_FS_A - EVENTOUT PE5 - TSC_G7_IO4 - - - SAI1_SCK_A - EVENTOUT PE6 - - - - - SAI1_SD_A - EVENTOUT PE7 - - - - - SAI1_SD_B - EVENTOUT PE8 - - - - - SAI1_SCK_B - EVENTOUT PE9 - - - - - SAI1_FS_B - EVENTOUT PE10 - TSC_G5_IO1 QUADSPI_CLK - - SAI1_MCLK_B - EVENTOUT PE11 - TSC_G5_IO2 QUADSPI_ BK1_NCS - - - - EVENTOUT PE12 - TSC_G5_IO3 QUADSPI_ BK1_IO0 - - - - EVENTOUT PE13 - TSC_G5_IO4 QUADSPI_ BK1_IO1 - - - - EVENTOUT PE14 - - QUADSPI_ BK1_IO2 - - - - EVENTOUT PE15 - - QUADSPI_ BK1_IO3 - - - - EVENTOUT PH0 - - - - - - - EVENTOUT PH1 - - - - - - - EVENTOUT PH3 - - - - - - - EVENTOUT Port DS11910 Rev 5 Port E Port H 81/207 Pinouts and pin description AF8 STM32L451xx Table 18. Alternate function AF8 to AF15(1) (continued) Pinouts and pin description 82/207 1. Refer to Table 17 for AF0 to AF7. DS11910 Rev 5 STM32L451xx STM32L451xx 5 Memory mapping Memory mapping Figure 13. STM32L451xx memory map 0xFFFF FFFF 0xBFFF FFFF Reserved Cortex™-M4 with FPU Internal Peripherals 7 0xA000 1400 QUADSPI registers 0xA000 1000 0xE000 0000 0x5FFF FFFF Reserved 6 0x5006 0C00 AHB2 0x4800 0000 Reserved 0xC000 0000 0x4002 4400 QUADSPI registers 5 AHB1 0x4002 0000 0xA000 1000 0x4001 5800 0xA000 0000 APB2 0x4001 0000 QUADSPI Flash bank 4 Reserved Reserved 0x4000 9800 0x9000 0000 APB1 0x4000 0000 0x1FFF FFFF 0x8000 0000 3 Reserved 0x6000 0000 0x1FFF 7810 Options Bytes 2 0x1FFF 7800 Reserved 0x1FFF 7400 Peripherals OTP area 0x4000 0000 0x1FFF 7000 System memory 1 0x2002 7FFF 0x2028 0000 0x1FFF 0000 SRAM2 Reserved 0x1000 8000 SRAM1 SRAM2 0x2000 0000 0x1000 0000 Reserved 0 0x0808 0000 CODE Flash memory 0x0800 0000 0x0000 0000 0x0008 0000 0x0000 0000 Reserved Reserved Flash, system memory or SRAM, depending on BOOT configuration MSv40981V2 DS11910 Rev 5 83/207 86 Memory mapping STM32L451xx Table 19. STM32L451xx memory map and peripheral register boundary addresses(1) Bus AHB2 - AHB1 APB2 84/207 Boundary address Size(bytes) Peripheral 0x5006 0800 - 0x5006 0BFF 1 KB 0x5004 0400 - 0x5006 07FF 158 KB 0x5004 0000 - 0x5004 03FF 1 KB ADC 0x5000 0000 - 0x5003 FFFF 16 KB Reserved 0x4800 2000 - 0x4FFF FFFF ~127 MB Reserved 0x4800 1C00 - 0x4800 1FFF 1 KB GPIOH 0x4800 1400 - 0x4800 1BFF 2 KB Reserved 0x4800 1000 - 0x4800 13FF 1 KB GPIOE 0x4800 0C00 - 0x4800 0FFF 1 KB GPIOD 0x4800 0800 - 0x4800 0BFF 1 KB GPIOC 0x4800 0400 - 0x4800 07FF 1 KB GPIOB 0x4800 0000 - 0x4800 03FF 1 KB GPIOA 0x4002 4400 - 0x47FF FFFF ~127 MB 0x4002 4000 - 0x4002 43FF 1 KB TSC 0x4002 3400 - 0x4002 3FFF 1 KB Reserved 0x4002 3000 - 0x4002 33FF 1 KB CRC 0x4002 2400 - 0x4002 2FFF 3 KB Reserved 0x4002 2000 - 0x4002 23FF 1 KB FLASH registers 0x4002 1400 - 0x4002 1FFF 3 KB Reserved 0x4002 1000 - 0x4002 13FF 1 KB RCC 0x4002 0800 - 0x4002 0FFF 2 KB Reserved 0x4002 0400 - 0x4002 07FF 1 KB DMA2 0x4002 0000 - 0x4002 03FF 1 KB DMA1 0x4001 6400 - 0x4001 FFFF 39 KB Reserved 0x4001 6000 - 0x4000 63FF 1 KB DFSDM 0x4001 5800 - 0x4001 5FFF 2 KB Reserved 0x4001 5400 - 0x4000 57FF 1 KB SAI1 0x4001 4800 - 0x4000 53FF 3 KB Reserved 0x4001 4400 - 0x4001 47FF 1 KB TIM16 0x4001 4000 - 0x4001 43FF 1 KB TIM15 0x4001 3C00 - 0x4001 3FFF 1 KB Reserved 0x4001 3800 - 0x4001 3BFF 1 KB USART1 0x4001 3400 - 0x4001 37FF 1 KB Reserved 0x4001 3000 - 0x4001 33FF 1 KB SPI1 DS11910 Rev 5 RNG Reserved Reserved STM32L451xx Memory mapping Table 19. STM32L451xx memory map and peripheral register boundary addresses(1) (continued) Bus APB2 Boundary address Size(bytes) 0x4001 2C00 - 0x4001 2FFF 1 KB TIM1 0x4001 2800 - 0x4001 2BFF 1 KB SDMMC1 0x4001 2000 - 0x4001 27FF 2 KB Reserved 0x4001 1C00 - 0x4001 1FFF 1 KB FIREWALL 0x4001 0800- 0x4001 1BFF 5 KB Reserved 0x4001 0400 - 0x4001 07FF 1 KB EXTI 0x4001 0200 - 0x4001 03FF 0x4001 0030 - 0x4001 01FF COMP 1 KB 0x4001 0000 - 0x4001 002F APB1 Peripheral VREFBUF SYSCFG 0x4000 9800 - 0x4000 FFFF 26 KB Reserved 0x4000 9400 - 0x4000 97FF 1 KB LPTIM2 0x4000 8800 - 0x4000 93FF 3 KB Reserved 0x4000 8400 - 0x4000 87FF 1 KB I2C4 0x4000 8000 - 0x4000 83FF 1 KB LPUART1 0x4000 7C00 - 0x4000 7FFF 1 KB LPTIM1 0x4000 7800 - 0x4000 7BFF 1 KB OPAMP 0x4000 7400 - 0x4000 77FF 1 KB DAC1 0x4000 7000 - 0x4000 73FF 1 KB PWR 0x4000 6800 - 0x4000 6FFF 2 KB Reserved 0x4000 6400 - 0x4000 67FF 1 KB CAN1 0x4000 6000 - 0x4000 63FF 1 KB CRS 0x4000 5C00- 0x4000 5FFF 1 KB I2C3 0x4000 5800 - 0x4000 5BFF 1 KB I2C2 0x4000 5400 - 0x4000 57FF 1 KB I2C1 0x4000 5000 - 0x4000 53FF 1 KB Reserved 0x4000 4C00 - 0x4000 4FFF 1 KB UART4 0x4000 4800 - 0x4000 4BFF 1 KB USART3 0x4000 4400 - 0x4000 47FF 1 KB USART2 0x4000 4000 - 0x4000 43FF 1 KB Reserved 0x4000 3C00 - 0x4000 3FFF 1 KB SPI3 0x4000 3800 - 0x4000 3BFF 1 KB SPI2 0x4000 3400 - 0x4000 37FF 1 KB Reserved 0x4000 3000 - 0x4000 33FF 1 KB IWDG 0x4000 2C00 - 0x4000 2FFF 1 KB WWDG DS11910 Rev 5 85/207 86 Memory mapping STM32L451xx Table 19. STM32L451xx memory map and peripheral register boundary addresses(1) (continued) Bus APB1 Boundary address Peripheral 0x4000 2800 - 0x4000 2BFF 1 KB RTC 0x4000 1400 - 0x4000 27FF 5 KB Reserved 0x4000 1000 - 0x4000 13FF 1 KB TIM6 0x4000 0800- 0x4000 0FFF 2 KB Reserved 0x4000 0400 - 0x4000 07FF 1 KB TIM3 0x4000 0000 - 0x4000 03FF 1 KB TIM2 1. The gray color is used for reserved boundary addresses. 86/207 Size(bytes) DS11910 Rev 5 STM32L451xx Electrical characteristics 6 Electrical characteristics 6.1 Parameter conditions Unless otherwise specified, all voltages are referenced to VSS. 6.1.1 Minimum and maximum values Unless otherwise specified, the minimum and maximum values are guaranteed in the worst conditions of ambient temperature, supply voltage and frequencies by tests in production on 100% of the devices with an ambient temperature at TA = 25 °C and TA = TAmax (given by the selected temperature range). Data based on characterization results, design simulation and/or technology characteristics are indicated in the table footnotes and are not tested in production. Based on characterization, the minimum and maximum values refer to sample tests and represent the mean value plus or minus three times the standard deviation (mean ±3σ). 6.1.2 Typical values Unless otherwise specified, typical data are based on TA = 25 °C, VDD = VDDA = 3 V. They are given only as design guidelines and are not tested. Typical ADC accuracy values are determined by characterization of a batch of samples from a standard diffusion lot over the full temperature range, where 95% of the devices have an error less than or equal to the value indicated (mean ±2σ). 6.1.3 Typical curves Unless otherwise specified, all typical curves are given only as design guidelines and are not tested. 6.1.4 Loading capacitor The loading conditions used for pin parameter measurement are shown in Figure 14. 6.1.5 Pin input voltage The input voltage measurement on a pin of the device is described in Figure 15. Figure 14. Pin loading conditions Figure 15. Pin input voltage MCU pin MCU pin C = 50 pF VIN MS19210V1 DS11910 Rev 5 MS19211V1 87/207 179 Electrical characteristics 6.1.6 STM32L451xx Power supply scheme Figure 16. Power supply scheme VBAT Backup circuitry (LSE, RTC, Backup registers) 1.55 – 3.6 V Power switch VDD VCORE n x VDD Regulator OUT n x 100 nF GPIOs IN +1 x 4.7 μF Level shifter VDDIO1 IO logic Kernel logic (CPU, Digital & Memories) n x VSS VDDA VDDA VREF ADC/ VREF+ DAC/ OPAMP/ VREFCOMPs/ VREFBUF 10 nF +1 μF 100 nF +1 μF VSSA MSv43827V2 Caution: 88/207 Each power supply pair (VDD/VSS, VDDA/VSSA etc.) must be decoupled with filtering ceramic capacitors as shown above. These capacitors must be placed as close as possible to, or below, the appropriate pins on the underside of the PCB to ensure the good functionality of the device. DS11910 Rev 5 STM32L451xx 6.1.7 Electrical characteristics Current consumption measurement Figure 17. Current consumption measurement scheme IDD_VBAT VBAT IDD VDD IDDA VDDA MSv41629V1 The IDD_ALL parameters given in Table 27 to Table 39 represent the total MCU consumption including the current supplying VDD, VDDA and VBAT. 6.2 Absolute maximum ratings Stresses above the absolute maximum ratings listed in Table 20: Voltage characteristics, Table 21: Current characteristics and Table 22: Thermal characteristics may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these conditions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. Exposure to maximum rating conditions for extended periods may affect device reliability. Device mission profile (application conditions) is compliant with JEDEC JESD47 qualification standard, extended mission profiles are available on demand. Table 20. Voltage characteristics(1) Symbol VDDX - VSS VIN(2) |ΔVDDx| |VSSx-VSS| Ratings Min Max Unit -0.3 4.0 V Input voltage on FT_xxx pins VSS-0.3 min (VDD, VDDA) + 4.0(3)(4) Input voltage on TT_xx pins VSS-0.3 4.0 Input voltage on any other pins VSS-0.3 4.0 Variations between different VDDX power pins of the same domain - 50 mV Variations between all the different ground pins(5) - 50 mV External main supply voltage (including VDD, VDDA, VBAT) V 1. All main power (VDD, VDDA, VBAT) and ground (VSS, VSSA) pins must always be connected to the external power supply, in the permitted range. 2. VIN maximum must always be respected. Refer to Table 21: Current characteristics for the maximum allowed injected current values. 3. This formula has to be applied only on the power supplies related to the IO structure described in the pin definition table. DS11910 Rev 5 89/207 179 Electrical characteristics STM32L451xx 4. To sustain a voltage higher than 4 V the internal pull-up/pull-down resistors must be disabled. 5. Include VREF- pin. Table 21. Current characteristics Symbol Ratings Max ∑IVDD Total current into sum of all VDD power lines (source)(1) 140 ∑IVSS (sink)(1) 140 Total current out of sum of all VSS ground lines IVDD(PIN) Maximum current into each VDD power pin (source)(1) 100 IVSS(PIN) Maximum current out of each VSS ground pin (sink)(1) 100 Output current sunk by any I/O and control pin except FT_f 20 Output current sunk by any FT_f pin 20 Output current sourced by any I/O and control pin 20 Total output current sunk by sum of all I/Os and control pins(2) 100 Total output current sourced by sum of all I/Os and control pins(2) 100 Injected current on FT_xxx, TT_xx, RST and B pins, except PA4, PA5 -5/+0(4) IIO(PIN) ∑IIO(PIN) IINJ(PIN)(3) Injected current on PA4, PA5 ∑|IINJ(PIN)| Unit mA -5/0 Total injected current (sum of all I/Os and control pins)(5) 25 1. All main power (VDD, VDDA, VBAT) and ground (VSS, VSSA) pins must always be connected to the external power supplies, in the permitted range. 2. This current consumption must be correctly distributed over all I/Os and control pins. The total output current must not be sunk/sourced between two consecutive power supply pins referring to high pin count QFP packages. 3. Positive injection (when VIN > VDDIOx) is not possible on these I/Os and does not occur for input voltages lower than the specified maximum value. 4. A negative injection is induced by VIN < VSS. IINJ(PIN) must never be exceeded. Refer also to Table 20: Voltage characteristics for the maximum allowed input voltage values. 5. When several inputs are submitted to a current injection, the maximum ∑|IINJ(PIN)| is the absolute sum of the negative injected currents (instantaneous values). Table 22. Thermal characteristics Symbol TSTG TJ 90/207 Ratings Storage temperature range Maximum junction temperature DS11910 Rev 5 Value Unit –65 to +150 °C 150 °C STM32L451xx Electrical characteristics 6.3 Operating conditions 6.3.1 General operating conditions Table 23. General operating conditions Symbol Parameter Conditions Min Max fHCLK Internal AHB clock frequency - 0 80 fPCLK1 Internal APB1 clock frequency - 0 80 fPCLK2 Internal APB2 clock frequency - 0 80 Standard operating voltage - VDD VDDA Analog supply voltage VIN V 3.6 V 1.55 3.6 V TT_xx I/O -0.3 VDDIOx+0.3 All I/O except TT_xx -0.3 Min(Min(VDD, VDDA)+3.6 V, 5.5 V)(2)(3) LQFP100 - 357 UFBGA100 - 267 PD PD Power dissipation at TA = 85 °C for suffix 6 LQFP64 - 345 UFBGA64 - 308 WLCSP64 - 377 LQFP48 - 346 UFQFPN48 - 690 LQFP100 - 89 UFBGA100 - 67 Power dissipation at TA = 125 °C for suffix 3(4) LQFP64 - 86 UFBGA64 - 77 WLCSP64 - 94 LQFP48 - 86 UFQFPN48 - 172 –40 85 –40 105 (1) ADC or COMP used 1.62 DAC or OPAMP used 1.8 VREFBUF used 2.4 Backup operating voltage I/O input voltage - 0 Ambient temperature for the suffix 6 version Maximum power dissipation Ambient temperature for the suffix 3 version Maximum power dissipation –40 125 Low-power dissipation(5) –40 130 TA MHz 3.6 ADC, DAC, OPAMP, COMP, VREFBUF not used VBAT 1.71 Unit Low-power dissipation(5) DS11910 Rev 5 V mW mW °C 91/207 179 Electrical characteristics STM32L451xx Table 23. General operating conditions (continued) Symbol TJ Parameter Conditions Junction temperature range Min Max Suffix 6 version –40 105 Suffix 3 version –40 130 Unit °C 1. When RESET is released functionality is guaranteed down to VBOR0 Min. 2. This formula has to be applied only on the power supplies related to the IO structure described by the pin definition table. Maximum I/O input voltage is the smallest value between Min(VDD, VDDA)+3.6 V and 5.5V. 3. For operation with voltage higher than Min (VDD, VDDA) +0.3 V, the internal Pull-up and Pull-Down resistors must be disabled. 4. If TA is lower, higher PD values are allowed as long as TJ does not exceed TJmax (see Section 7.8: Thermal characteristics). 5. In low-power dissipation state, TA can be extended to this range as long as TJ does not exceed TJmax (see Section 7.8: Thermal characteristics). 6.3.2 Operating conditions at power-up / power-down The parameters given in Table 24 are derived from tests performed under the ambient temperature condition summarized in Table 23. Table 24. Operating conditions at power-up / power-down Symbol Parameter Conditions VDD rise time rate tVDD Max 0 ∞ 10 ∞ 0 ∞ 10 ∞ - VDD fall time rate VDDA rise time rate tVDDA Min - VDDA fall time rate Unit µs/V µs/V The requirements for power-up/down sequence specified in Section 3.9.1: Power supply schemes must be respected. 6.3.3 Embedded reset and power control block characteristics The parameters given in Table 25 are derived from tests performed under the ambient temperature conditions summarized in Table 23: General operating conditions. Table 25. Embedded reset and power control block characteristics Symbol tRSTTEMPO(2) 92/207 Parameter Reset temporization after BOR0 is detected VBOR0(2) Brown-out reset threshold 0 VBOR1 Brown-out reset threshold 1 VBOR2 Brown-out reset threshold 2 Conditions(1) Min Typ Max Unit - 250 400 μs Rising edge 1.62 1.66 1.7 Falling edge 1.6 1.64 1.69 Rising edge 2.06 2.1 2.14 Falling edge 1.96 2 2.04 Rising edge 2.26 2.31 2.35 Falling edge 2.16 2.20 2.24 VDD rising DS11910 Rev 5 V V V STM32L451xx Electrical characteristics Table 25. Embedded reset and power control block characteristics (continued) Symbol Conditions(1) Min Typ Max Rising edge 2.56 2.61 2.66 Falling edge 2.47 2.52 2.57 Rising edge 2.85 2.90 2.95 Falling edge 2.76 2.81 2.86 Rising edge 2.1 2.15 2.19 Falling edge 2 2.05 2.1 Rising edge 2.26 2.31 2.36 Falling edge 2.15 2.20 2.25 Rising edge 2.41 2.46 2.51 Falling edge 2.31 2.36 2.41 Rising edge 2.56 2.61 2.66 Falling edge 2.47 2.52 2.57 Rising edge 2.69 2.74 2.79 Falling edge 2.59 2.64 2.69 Rising edge 2.85 2.91 2.96 Falling edge 2.75 2.81 2.86 Rising edge 2.92 2.98 3.04 Falling edge 2.84 2.90 2.96 Hysteresis in continuous Hysteresis voltage of BORH0 mode - 20 - Hysteresis in other mode - 30 - Parameter VBOR3 Brown-out reset threshold 3 VBOR4 Brown-out reset threshold 4 VPVD0 Programmable voltage detector threshold 0 VPVD1 PVD threshold 1 VPVD2 PVD threshold 2 VPVD3 PVD threshold 3 VPVD4 PVD threshold 4 VPVD5 PVD threshold 5 VPVD6 PVD threshold 6 Vhyst_BORH0 Unit V V V V V V V V V mV Hysteresis voltage of BORH (except BORH0) and PVD - - 100 - mV BOR(3) (except BOR0) and IDD (BOR_PVD)(2) PVD consumption from VDD - - 1.1 1.6 µA Vhyst_BOR_PVD VPVM3 VDDA peripheral voltage monitoring Rising edge 1.61 1.65 1.69 Falling edge 1.6 1.64 1.68 VPVM4 VDDA peripheral voltage monitoring Rising edge 1.78 1.82 1.86 Falling edge 1.77 1.81 1.85 V V Vhyst_PVM3 PVM3 hysteresis - - 10 - mV Vhyst_PVM4 PVM4 hysteresis - - 10 - mV PVM1 consumption from VDD - - 0.2 - µA - - 2 - µA IDD (PVM1) (2) IDD PVM3 and PVM4 (PVM3/PVM4) consumption from VDD (2) DS11910 Rev 5 93/207 179 Electrical characteristics STM32L451xx 1. Continuous mode means Run/Sleep modes, or temperature sensor enable in Low-power run/Low-power sleep modes. 2. Guaranteed by design. 3. BOR0 is enabled in all modes (except shutdown) and its consumption is therefore included in the supply current characteristics tables. 94/207 DS11910 Rev 5 STM32L451xx 6.3.4 Electrical characteristics Embedded voltage reference The parameters given in Table 26 are derived from tests performed under the ambient temperature and supply voltage conditions summarized in Table 23: General operating conditions. Table 26. Embedded internal voltage reference Symbol VREFINT Parameter Internal reference voltage Conditions –40 °C < TA < +130 °C Min Typ Max Unit 1.182 1.212 1.232 V tS_vrefint (1) ADC sampling time when reading the internal reference voltage - 4(2) - - µs tstart_vrefint Start time of reference voltage buffer when ADC is enable - - 8 12(2) µs - - 12.5 20(2) µA VREFINT buffer consumption from VDD when converted by IDD(VREFINTBUF) ADC ∆VREFINT TCoeff Internal reference voltage spread over the temperature range VDD = 3 V - 5 7.5(2) mV Temperature coefficient –40°C < TA < +130°C - 30 50(2) ppm/°C ppm ppm/V ACoeff Long term stability 1000 hours, T = 25°C - 300 1000(2) VDDCoeff Voltage coefficient 3.0 V < VDD < 3.6 V - 250 1200(2) 24 25 26 49 50 51 74 75 76 VREFINT_DIV1 1/4 reference voltage VREFINT_DIV2 1/2 reference voltage VREFINT_DIV3 3/4 reference voltage - % VREFINT 1. The shortest sampling time can be determined in the application by multiple iterations. 2. Guaranteed by design. DS11910 Rev 5 95/207 179 Electrical characteristics STM32L451xx Figure 18. VREFINT versus temperature V 1.235 1.23 1.225 1.22 1.215 1.21 1.205 1.2 1.195 1.19 1.185 -40 -20 0 20 40 Mean 60 Min 80 100 120 °C Max MSv40169V1 96/207 DS11910 Rev 5 STM32L451xx 6.3.5 Electrical characteristics Supply current characteristics The current consumption is a function of several parameters and factors such as the operating voltage, ambient temperature, I/O pin loading, device software configuration, operating frequencies, I/O pin switching rate, program location in memory and executed binary code. The current consumption is measured as described in Figure 17: Current consumption measurement scheme. Typical and maximum current consumption The MCU is placed under the following conditions: • All I/O pins are in analog input mode • All peripherals are disabled except when explicitly mentioned • The Flash memory access time is adjusted with the minimum wait states number, depending on the fHCLK frequency (refer to the table “Number of wait states according to CPU clock (HCLK) frequency” available in the RM0394 reference manual). • When the peripherals are enabled fPCLK = fHCLK The parameters given in Table 27 to Table 40 are derived from tests performed under ambient temperature and supply voltage conditions summarized in Table 23: General operating conditions. DS11910 Rev 5 97/207 179 running from Flash, ART enable (Cache ON Prefetch OFF) Conditions Symbol Parameter - Voltage scaling DS11910 Rev 5 IDD_ALL (LPRun) Unit 55 °C 85 °C 2.65 2.75 2.90 3.20 3.75 2.15 1.70 1.75 1.95 2.20 2.80 1.10 1.45 0.95 1.00 1.15 1.45 2.00 0.595 0.760 1.10 0.55 0.60 0.75 1.05 1.60 0.295 0.320 0.420 0.580 0.910 0.35 0.40 0.55 0.85 1.40 0.205 0.235 0.330 0.495 0.825 0.25 0.30 0.45 0.75 1.30 100 kHz 0.130 0.155 0.250 0.415 0.745 0.15 0.25 0.40 0.65 1.25 80 MHz 8.45 8.50 8.65 8.90 9.25 9.45 9.50 9.75 10.10 10.75 72 MHz 7.65 7.70 7.85 8.05 8.45 8.50 8.60 8.80 9.15 9.85 64 MHz 6.80 6.85 7.00 7.20 7.60 7.60 7.70 7.90 8.25 8.90 Range 1 48 MHz 5.10 5.15 5.25 5.45 5.85 5.70 5.80 6.00 6.35 7.00 32 MHz 3.45 3.50 3.60 3.80 4.20 3.85 3.95 4.15 4.50 5.15 24 MHz 2.60 2.65 2.80 2.95 3.35 2.95 3.05 3.20 3.55 4.20 16 MHz 1.80 1.85 1.95 2.15 2.50 2.00 2.10 2.30 2.60 3.25 2 MHz 225 260 365 550 900 275 335 470 770 1400 1 MHz 130 160 270 450 800 170 225 375 670 1300 400 kHz 73.0 99.5 205 385 735 105 165 325 600 1250 100 kHz 38.0 71.0 175 355 705 70 140 315 565 1200 Range 2 IDD_ALL (Run) MAX(1) TYP fHCLK = fHSE up to 48MHz included, Supply bypass mode current in PLL ON above Run mode 48 MHz all peripherals disable Supply current in fHCLK = fMSI Low-power all peripherals disable run mode 25 °C 55 °C 85 °C 26 MHz 2.35 2.40 2.50 2.65 3.00 16 MHz 1.50 1.55 1.65 1.80 8 MHz 0.815 0.845 0.940 4 MHz 0.465 0.495 2 MHz 1 MHz fHCLK 105 °C 125 °C mA µA STM32L451xx 1. Guaranteed by characterization results, unless otherwise specified. 105 °C 125 °C 25 °C Electrical characteristics 98/207 Table 27. Current consumption in Run and Low-power run modes, code with data processing running from Flash, ART disable Conditions Symbol Parameter - Voltage scaling Unit 25 °C 55 °C 85 °C 2.75 2.80 2.90 3.10 3.40 16 MHz 1.95 2.00 2.10 2.25 8 MHz 1.10 1.15 1.25 1.40 4 MHz 0.640 0.670 0.765 0.935 2 MHz 0.380 0.405 0.505 0.670 1.00 0.45 0.50 0.65 0.95 1.50 1 MHz 0.250 0.275 0.375 0.540 0.865 0.30 0.35 0.50 0.80 1.35 100 kHz 0.135 0.160 0.255 0.420 0.750 0.15 0.25 0.40 0.65 1.25 80 MHz 8.85 8.90 9.05 9.30 9.70 10.0 10.5 10.5 11.0 11.5 72 MHz 8.00 8.05 8.20 8.40 8.85 9.05 9.15 9.35 9.70 10.5 64 MHz 7.90 7.95 8.10 8.35 8.75 8.95 9.10 9.35 9.70 10.5 Range 1 48 MHz 6.60 6.65 6.80 7.05 7.45 7.55 7.65 7.90 8.30 9.00 32 MHz 4.75 4.80 4.95 5.15 5.55 5.40 5.50 5.75 6.10 6.80 24 MHz 3.60 3.65 3.80 4.00 4.35 4.10 4.20 4.40 4.75 5.40 16 MHz 2.60 2.65 2.75 2.95 3.35 3.00 3.05 3.25 3.60 4.25 2 MHz 340 360 470 650 1000 400 455 575 880 1550 1 MHz 175 215 320 500 855 225 285 420 720 1350 400 kHz 89.5 120 225 405 760 130 185 340 620 1250 100 kHz 42.5 75.5 180 360 715 75 145 320 575 1200 fHCLK 26 MHz Range 2 IDD_ALL (Run) DS11910 Rev 5 IDD_ALL (LPRun) MAX(1) TYP fHCLK = fHSE up to 48MHz included, Supply bypass mode current in PLL ON above Run mode 48 MHz all peripherals disable Supply current in fHCLK = fMSI Low-power all peripherals disable run 55 °C 85 °C 105 °C 125 °C 3.15 3.25 3.40 3.70 4.30 2.60 2.25 2.30 2.50 2.75 3.35 1.75 1.25 1.35 1.50 1.75 2.35 1.25 0.75 0.80 0.95 1.25 1.80 mA µA 99/207 Electrical characteristics 1. Guaranteed by characterization results, unless otherwise specified. 105 °C 125 °C 25 °C STM32L451xx Table 28. Current consumption in Run and Low-power run modes, code with data processing Conditions Symbol Parameter - Voltage scaling Range 2 IDD_ALL (Run) Supply current in Run mode DS11910 Rev 5 fHCLK = fHSE up to 48MHz included, bypass mode PLL ON above 48 MHz all peripherals disable Range 1 IDD_ALL (LPRun) Supply current in low-power run mode fHCLK = fMSI all peripherals disable FLASH in power-down MAX(1) TYP fHCLK 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C 26 MHz 2.40 2.40 2.55 2.70 3.05 2.70 2.75 2.90 3.20 3.80 16 MHz 1.50 1.55 1.65 1.80 2.15 1.70 1.80 1.95 2.25 2.80 8 MHz 0.820 0.850 0.950 1.10 1.45 0.95 1.00 1.15 1.45 2.00 4 MHz 0.470 0.500 0.600 0.765 1.10 0.55 0.60 0.75 1.05 1.60 2 MHz 0.295 0.325 0.420 0.585 0.915 0.35 0.40 0.55 0.85 1.40 1 MHz 0.210 0.235 0.330 0.495 0.825 0.25 0.30 0.45 0.75 1.30 100 kHz 0.130 0.155 0.250 0.415 0.750 0.15 0.25 0.35 0.65 1.25 80 MHz 8.55 8.60 8.75 8.95 9.35 9.55 9.65 9.85 10.5 11.0 72 MHz 7.70 7.80 7.90 8.15 8.50 8.60 8.70 8.90 9.25 9.95 64 MHz 6.90 6.95 7.10 7.30 7.70 7.70 7.75 7.95 8.35 9.00 48 MHz 5.15 5.20 5.30 5.55 5.90 5.75 5.85 6.05 6.40 7.05 32 MHz 3.45 3.50 3.65 3.85 4.25 3.90 4.00 4.20 4.50 5.15 24 MHz 2.65 2.70 2.80 3.00 3.40 3.00 3.05 3.25 3.55 4.20 16 MHz 1.80 1.85 1.95 2.15 2.55 2.05 2.10 2.30 2.60 3.25 2 MHz 220 255 360 540 895 270 330 460 760 1400 1 MHz 120 155 260 440 795 165 215 370 660 1300 400 kHz 60.0 92.0 195 375 730 100 160 330 585 1250 100 kHz 36.0 62.5 165 345 695 63.0 130 305 555 1200 Unit Electrical characteristics 100/207 Table 29. Current consumption in Run and Low-power run modes, code with data processing running from SRAM1 mA µA 1. Guaranteed by characterization results, unless otherwise specified. STM32L451xx STM32L451xx Electrical characteristics Table 30. Typical current consumption in Run and Low-power run modes, with different codes running from Flash, ART enable (Cache ON Prefetch OFF) Conditions - IDD_ALL (Run) Supply current in Run mode fHCLK = fHSE up to 48 MHz included, bypass mode PLL ON above 48 MHz all peripherals disable Voltage scaling Range 2 fHCLK = 26 MHz Parameter Supply current in fHCLK = fMSI = 2 MHz Low-power all peripherals disable run Unit 25 °C 25 °C Reduced code(1) 2.35 90 Coremark 2.65 102 Dhrystone 2.1 2.75 Fibonacci 2.60 100 2.35 90 Reduced code 8.45 106 Coremark 9.45 118 Dhrystone 2.1 9.85 Fibonacci 9.25 116 8.45 106 Reduced code 225 113 Coremark 260 130 Dhrystone 2.1 270 Fibonacci 245 123 While(1) 285 143 While(1) While(1) (1) IDD_ALL (LPRun) TYP Unit Code (1) Range 1 fHCLK = 80 MHz Symbol TYP mA mA µA 106 123 135 µA/MHz µA/MHz µA/MHz 1. Reduced code used for characterization results provided in Table 27, Table 28, Table 29. DS11910 Rev 5 101/207 179 Electrical characteristics STM32L451xx Table 31. Typical current consumption in Run and Low-power run modes, with different codes running from Flash, ART disable Conditions Parameter - IDD_ALL (Run) IDD_ALL (LPRun) Supply current in Run mode fHCLK = fHSE up to 48 MHz included, bypass mode PLL ON above 48 MHz all peripherals disable Supply current in fHCLK = fMSI = 2 MHz Low-power all peripherals disable run TYP Unit Voltage scaling Range 1 Range 2 fHCLK = 80 MHz fHCLK = 26 MHz Symbol TYP Code Unit 25 °C 25 °C Reduced code(1) 2.75 106 Coremark 2.50 96 Dhrystone 2.1 2.50 Fibonacci 2.30 88 While(1) 2.20 84.6 Reduced code(1) 8.85 111 Coremark 8.15 102 Dhrystone 2.1 8.15 Fibonacci 7.55 While(1) 7.95 99 Reduced code(1) 340 170 mA mA 96 102 µA/MHz µA/MHz 94 Coremark 380 Dhrystone 2.1 355 190 Fibonacci 355 178 While(1) 405 203 µA 178 µA/MHz 1. Reduced code used for characterization results provided in Table 27, Table 28, Table 29. Table 32. Typical current consumption in Run and Low-power run modes, with different codes running from SRAM1 Conditions Parameter - IDD_ALL (Run) IDD_ALL (LPRun) fHCLK = fHSE up to 48 MHz included, bypass mode Supply current in PLL ON above Run mode 48 MHz all peripherals disable Voltage scaling Range 1 Range 2 fHCLK = 80 MHz fHCLK = 26 MHz Symbol Supply current in fHCLK = fMSI = 2 MHz Low-power all peripherals disable run TYP Unit Code Unit 25 °C 25 °C Reduced code(1) 2.40 92 Coremark 2.20 Dhrystone 2.1 2.35 85 mA 90 Fibonacci 2.20 85 While(1) 2.30 88 Reduced code(1) 8.55 107 Coremark 7.75 8.45 Fibonacci 7.80 98 While(1) 8.75 109 Reduced code(1) 220 110 Coremark 190 106 µA/MHz 95 µA Dhrystone 2.1 215 Fibonacci 200 100 While(1) 210 105 DS11910 Rev 5 µA/MHz 97 mA Dhrystone 2.1 1. Reduced code used for characterization results provided in Table 27, Table 28, Table 29. 102/207 TYP 108 µA/MHz Conditions Symbol Parameter - Voltage scaling Range 2 IDD_ALL (Sleep) DS11910 Rev 5 IDD_ALL (LPSleep) Supply current in sleep mode, fHCLK = fHSE up to 48 MHz included, bypass mode pll ON above 48 MHz all peripherals disable MAX(1) TYP Unit fHCLK 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 26 MHz 0.700 0.730 0.830 1.00 16 MHz 0.475 0.505 0.605 0.775 1.10 0.55 0.65 0.80 1.05 1.65 8 MHz 0.300 0.325 0.425 0.590 0.920 0.35 0.45 0.60 0.85 1.45 4 MHz 0.210 0.235 0.335 0.500 0.830 0.25 0.30 0.45 0.75 1.35 2 MHz 0.165 0.190 0.290 0.455 0.785 0.20 0.25 0.40 0.70 1.25 1 MHz 0.145 0.170 0.265 0.430 0.760 0.15 0.25 0.40 0.65 1.25 100 kHz 0.125 0.150 0.245 0.410 0.740 0.15 0.20 0.35 0.65 1.20 80 MHz 2.30 2.35 2.45 2.65 3.05 2.55 2.65 2.85 3.15 3.80 72 MHz 2.10 2.15 2.25 2.45 2.80 2.35 2.40 2.60 2.90 3.55 64 MHz 1.90 1.90 2.05 2.25 2.60 2.10 2.20 2.35 2.70 3.35 1.35 0.80 55 °C 85 °C 0.90 1.05 105 °C 125 °C 1.30 1.90 Range 1 48 MHz 1.40 1.40 1.55 1.75 2.15 1.60 1.65 1.85 2.15 2.80 32 MHz 0.970 1.00 1.15 1.30 1.70 1.10 1.20 1.40 1.70 2.35 Supply current in =f f low-power HCLK MSI all peripherals disable sleep mode 24 MHz 0.765 0.800 0.920 1.10 1.50 0.90 0.95 1.15 1.45 2.10 16 MHz 0.555 0.590 0.705 0.895 1.25 0.65 0.75 0.90 1.20 1.85 2 MHz 76.0 110 215 395 745 120 185 355 610 1250 1 MHz 54.0 86.5 195 370 725 88.5 160 335 585 1250 400 kHz 39.0 70.5 175 355 710 68.5 140 320 570 1200 100 kHz 35.5 75.0 195 345 715 66.0 130 305 560 1200 mA µA 103/207 Electrical characteristics 1. Guaranteed by characterization results, unless otherwise specified. STM32L451xx Table 33. Current consumption in Sleep and Low-power sleep modes, Flash ON Conditions Symbol Parameter Voltage scaling - IDD_ALL (LPSleep) Supply current in low-power sleep mode fHCLK = fMSI all peripherals disable MAX(1) TYP Unit fHCLK 25 °C 55 °C 2 MHz 76.5 105 85 °C 220 105 °C 125 °C 25 °C 410 740 110 55 °C 85 °C 175 350 105 °C 125 °C 600 1250 1 MHz 54.0 81.0 195 385 715 81.5 155 325 570 1200 400 kHz 28.0 64.5 175 370 695 60.5 130 305 555 1200 100 kHz 21.5 55.0 170 360 690 58.5 120 300 550 1200 µA Electrical characteristics 104/207 Table 34. Current consumption in Low-power sleep modes, Flash in power-down 1. Guaranteed by characterization results, unless otherwise specified. Table 35. Current consumption in Stop 2 mode DS11910 Rev 5 Symbol Parameter IDD_ALL (Stop 2) Supply current in Stop 2 mode, RTC disabled Conditions - - RTC clocked by LSI IDD_ALL (Stop 2 with RTC) Supply current in RTC clocked by LSE Stop 2 mode, bypassed at 32768 Hz RTC enabled VDD 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 1.8 V 2.05 5.40 19.0 44.0 97.0 2.4 V 2.10 5.45 19.0 44.5 98.5 3V 2.05 5.55 19.5 45.0 3.6 V 2.05 5.65 20.0 1.8 V 2.30 5.65 2.4 V 2.35 5.80 3V 2.50 3.6 V 1.8 V 105 °C 125 °C 4.00 11.5 41.5 100 220 4.05 11.5 42.0 100 225 100 4.10 12.0 43.0 105 230 46.5 105 4.20 12.0 44.0 105 235 19.0 44.0 97.0 4.50 12.0 42.0 100 220 19.5 44.5 99.0 4.65 12.0 42.5 100 225 5.90 20.0 45.5 100 4.90 12.5 43.5 105 230 2.60 6.15 20.5 47.0 105 5.20 13.0 44.5 105 235 2.60 6.05 21.0 48.0 97.0 - - - - - 2.4 V 2.55 6.20 21.0 49.0 98.5 - - - - - 3V 2.80 6.35 21.5 49.5 100 - - - - - 3.6 V 2.85 6.60 22.5 51.5 105 - - - - - 1.8 V 2.40 5.70 19.0 44.5 98.0 - - - - - 2.4 V 2.50 5.85 19.5 45.0 99.5 - - - - - 3V 2.60 6.00 20.0 46.0 100 - - - - - 3.6 V 2.65 6.25 20.5 47.0 105 - - - - - Unit µA µA STM32L451xx RTC clocked by LSE quartz(2) in low drive mode MAX(1) TYP Symbol Parameter Supply current IDD_ALL during wakeup (wakeup from from Stop 2 Stop 2) mode Conditions - MAX(1) TYP VDD 25 °C 55 °C Wakeup clock is MSI = 48 MHz, voltage Range 1. See (3). 3V 1.85 - - - - Wakeup clock is MSI = 4 MHz, voltage Range 2. See (3). 3V 1.50 - - - Wakeup clock is HSI16 = 16 MHz, voltage Range 1. See (3). 3V 1.55 - - - 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C - - - - - - - - - - - - - - - - - Unit STM32L451xx Table 35. Current consumption in Stop 2 mode (continued) mA DS11910 Rev 5 1. Guaranteed based on test during characterization, unless otherwise specified. 2. Based on characterization done with a 32.768 kHz crystal (MC306-G-06Q-32.768, manufacturer JFVNY) with two 6.8 pF loading capacitors. 3. Wakeup with code execution from Flash. Average value given for a typical wakeup time as specified in Table 42: Low-power mode wakeup timings. Electrical characteristics 105/207 Symbol Parameter IDD_ALL (Stop 1) Supply current in Stop 1 mode, RTC disabled Conditions - - RTC clocked by LSI DS11910 Rev 5 Supply IDD_ALL current in stop RTC clocked by LSE (Stop 1 with 1 mode, bypassed, at 32768 Hz RTC) RTC enabled RTC clocked by LSE quartz(2) in low drive mode Wakeup clock MSI = 48 MHz, voltage Range 1. See (3). Supply Wakeup clock MSI = 4 MHz, IDD_ALL current during voltage Range 2. (wakeup wakeup from from Stop1) See (3). Stop 1 Wakeup clock HSI16 = 16 MHz, voltage Range 1. See (3). MAX(1) TYP VDD 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C 1.8 V 9.85 29.0 100 225 430 17.0 49.5 185 395 850 2.4 V 9.85 29.5 100 225 435 17.0 49.5 185 395 850 3V 9.90 29.5 100 225 435 17.5 50.0 185 400 850 3.6 V 10.0 28.0 105 230 410 17.5 50.5 190 405 860 1.8 V 10.5 29.5 100 225 430 17.0 50.0 185 395 840 2.4 V 10.5 29.5 100 225 435 17.0 50.5 185 395 845 3V 10.5 30.0 105 225 435 17.5 50.5 185 400 855 3.6 V 10.5 30.0 105 230 440 17.5 51.5 190 405 860 1.8 V 10.0 29.5 100 225 435 - - - - - 2.4 V 10.0 29.5 100 225 435 - - - - - 3V 10.5 30.0 105 225 440 - - - - - 3.6 V 11.0 30.5 105 230 440 - - - - - 1.8 V 10.0 29.0 99.5 220 435 - - - - - 2.4 V 10.0 29.0 99.5 220 435 - - - - - 3V 10.0 29.0 100 220 440 - - - - - 3.6 V 10.5 29.5 100 225 440 - - - - - 3V 1.15 - - - - - - - - - 3V 1.20 - - - - - - - - - 3V 1.20 - - - - - - - - - 2. Based on characterization done with a 32.768 kHz crystal (MC306-G-06Q-32.768, manufacturer JFVNY) with two 6.8 pF loading capacitors. 3. Wakeup with code execution from Flash. Average value given for a typical wakeup time as specified in Table 42: Low-power mode wakeup timings. µA µA mA STM32L451xx 1. Guaranteed based on test during characterization, unless otherwise specified. Unit Electrical characteristics 106/207 Table 36. Current consumption in Stop 1 mode Symbol Parameter IDD_ALL (Stop 0) Supply current in Stop 0 mode, RTC disabled Conditions VDD MAX(1) TYP 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C 1.8 V 125 150 240 390 645 145 190 350 600 1150 2.4 V 125 150 240 390 645 150 195 355 605 1150 3V 125 150 245 395 650 155 195 360 610 1150 3.6 V 125 155 245 400 655 155 200 365 615 1150(2) Unit STM32L451xx Table 37. Current consumption in Stop 0 µA 1. Guaranteed by characterization results, unless otherwise specified. 2. Guaranteed by test in production. DS11910 Rev 5 Electrical characteristics 107/207 Symbol IDD_ALL (Standby) Parameter Supply current in Standby mode (backup registers retained), RTC disabled Conditions - no independent watchdog with independent watchdog DS11910 Rev 5 RTC clocked by LSI, no independent watchdog IDD_ALL (Standby with RTC) Supply current in Standby mode (backup registers retained), RTC enabled RTC clocked by LSI, with independent watchdog RTC clocked by LSE bypassed at 32768Hz MAX(1) TYP VDD 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C 1.8 V 100 270 1200 3300 8650 205 650 3250 9250 25000 2.4 V 110 305 1400 3850 10000 225 750 3750 11000 29000 3V 125 360 1650 4550 12000 290 950 4450 13000 33500 3.6 V 160 445 2000 5500 14500 355 1150 5250 15000 38500 1.8 V 265 435 1350 3450 8700 - - - - - 2.4 V 335 540 1650 4100 10500 - - - - - 3V 420 655 1950 4850 12500 - - - - - 3.6 V 580 895 2450 5950 14500 - - - - - 1.8 V 345 505 1400 3450 8600 720 1150 3750 9550 25000 2.4 V 420 620 1650 4050 10000 875 1450 4400 11500 29000 3V 510 745 2000 4750 12000 1070 1700 5100 13500 34000 3.6 V 635 915 2450 5900 14500 1320 2100 6000 15500 39000 1.8 V 375 540 1450 3550 8800 - - - - - 2.4 V 490 690 1800 4250 10500 - - - - - 3V 620 860 2150 5100 12500 - - - - - 3.6 V 845 1150 2700 6200 15000 - - - - - 1.8 V 395 - - - - - - - - - 2.4 V 500 - - - - - - - - - 3V 625 - - - - - - - - - 795 - - - - - - - - - 1.8 V 375 550 1500 3550 8800 - - - - - 2.4 V RTC clocked by LSE quartz (2) in low drive mode 3 V 460 665 1750 4250 10500 - - - - - 565 810 2100 5050 12500 - - - - - 3.6 V 720 1000 2600 5900 15000 - - - - - nA nA nA STM32L451xx 3.6 V Unit Electrical characteristics 108/207 Table 38. Current consumption in Standby mode Symbol IDD_ALL (SRAM2)(3) IDD_ALL (wakeup from Standby) Parameter Supply current to be added in Standby mode when SRAM2 is retained Supply current during wakeup from Standby mode Conditions - VDD - Wakeup clock is MSI = 4 MHz. See (4). MAX(1) TYP 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C 1.8 V 250 730 2700 6350 13850 575 1800 6350 14500 32000 2.4 V 250 740 2700 6150 14000 620 1800 6450 14500 32000 3V 255 740 2700 6450 13500 645 1850 6500 15000 32500 3.6 V 255 755 2800 6500 13500 790 1950 6500 15000 33000 3V 2.00 - - - - - - - - - Unit STM32L451xx Table 38. Current consumption in Standby mode (continued) nA mA 1. Guaranteed by characterization results, unless otherwise specified. 2. Based on characterization done with a 32.768 kHz crystal (MC306-G-06Q-32.768, manufacturer JFVNY) with two 6.8 pF loading capacitors. DS11910 Rev 5 3. The supply current in Standby with SRAM2 mode is: IDD_ALL(Standby) + IDD_ALL(SRAM2). The supply current in Standby with RTC with SRAM2 mode is: IDD_ALL(Standby + RTC) + IDD_ALL(SRAM2). 4. Wakeup with code execution from Flash. Average value given for a typical wakeup time as specified in Table 42: Low-power mode wakeup timings. Table 39. Current consumption in Shutdown mode Symbol IDD_ALL (Shutdown) Parameter - - MAX(1) TYP VDD 25 °C 55 °C 1.8 V 19.0 120 2.4 V 26.0 3V 37.0 3.6 V 67.0 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C 720 2200 6400 38.0 350 2050 6350 19500 145 855 2600 7450 62.0 400 2400 7450 22500 185 1050 3100 8700 105 500 2850 8750 26000 260 1350 3950 11000 160 650 3500 10500 30000 Unit nA 109/207 Electrical characteristics Supply current in Shutdown mode (backup registers retained) RTC disabled Conditions Symbol IDD_ALL (Shutdown with RTC) Parameter Supply current in Shutdown mode (backup registers retained) RTC enabled DS11910 Rev 5 Supply current IDD_ALL during wakeup (wakeup from from Shutdown Shutdown) mode Conditions - VDD RTC clocked by LSE bypassed at 32768 Hz RTC clocked by LSE quartz (2) in low drive mode Wakeup clock is MSI = 4 MHz. See (3). MAX(1) TYP 25 °C 55 °C 1.8 V 165 275 2.4 V 235 3V 325 3.6 V 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C 950 2600 6550 - - - - - 370 1150 3100 7650 - - - - - 485 1450 3750 9050 - - - - - 445 655 1900 4800 11500 - - - - - 1.8 V 290 410 1050 2550 6700 - - - - - 2.4 V 375 515 1250 3050 7800 - - - - - 3V 480 645 1550 3700 8800 - - - - - 3.6 V 625 840 1950 4950 11500 - - - - - 3V 1.00 - - - - - - - - - Unit nA Electrical characteristics 110/207 Table 39. Current consumption in Shutdown mode (continued) mA 1. Guaranteed by characterization results, unless otherwise specified. 2. Based on characterization done with a 32.768 kHz crystal (MC306-G-06Q-32.768, manufacturer JFVNY) with two 6.8 pF loading capacitors. 3. Wakeup with code execution from Flash. Average value given for a typical wakeup time as specified in Table 42: Low-power mode wakeup timings. Table 40. Current consumption in VBAT mode Symbol Parameter Conditions - RTC disabled IDD_VBAT (VBAT) Backup domain supply current VBAT 25 °C 55 °C 1.8 V 3.00 - - - - 2.4 V 4.00 - - - 3V 5.00 - - - 3.6 V 11.0 - - - - - - - - - 1.8 V 145 165 285 550 - - - - - - 2.4 V 205 235 370 670 - - - - - - 3V 285 315 470 820 - - - - - - 3.6 V 375 430 715 1350 - - - - - - 1. Guaranteed by characterization results, unless otherwise specified. 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C - - - - - - - - - - - - - - - - - Unit nA STM32L451xx RTC enabled and clocked by LSE bypassed at 32768 Hz MAX(1) TYP STM32L451xx Electrical characteristics I/O system current consumption The current consumption of the I/O system has two components: static and dynamic. I/O static current consumption All the I/Os used as inputs with pull-up generate current consumption when the pin is externally held low. The value of this current consumption can be simply computed by using the pull-up/pull-down resistors values given in Table 61: I/O static characteristics. For the output pins, any external pull-down or external load must also be considered to estimate the current consumption. Additional I/O current consumption is due to I/Os configured as inputs if an intermediate voltage level is externally applied. This current consumption is caused by the input Schmitt trigger circuits used to discriminate the input value. Unless this specific configuration is required by the application, this supply current consumption can be avoided by configuring these I/Os in analog mode. This is notably the case of ADC input pins which should be configured as analog inputs. Caution: Any floating input pin can also settle to an intermediate voltage level or switch inadvertently, as a result of external electromagnetic noise. To avoid current consumption related to floating pins, they must either be configured in analog mode, or forced internally to a definite digital value. This can be done either by using pull-up/down resistors or by configuring the pins in output mode. I/O dynamic current consumption In addition to the internal peripheral current consumption measured previously (see Table 41: Peripheral current consumption), the I/Os used by an application also contribute to the current consumption. When an I/O pin switches, it uses the current from the I/O supply voltage to supply the I/O pin circuitry and to charge/discharge the capacitive load (internal or external) connected to the pin: I SW = V DDIOx × f SW × C where ISW is the current sunk by a switching I/O to charge/discharge the capacitive load VDDIOx is the I/O supply voltage fSW is the I/O switching frequency C is the total capacitance seen by the I/O pin: C = CINT+ CEXT + CS CS is the PCB board capacitance including the pad pin. The test pin is configured in push-pull output mode and is toggled by software at a fixed frequency. DS11910 Rev 5 111/207 179 Electrical characteristics STM32L451xx On-chip peripheral current consumption The current consumption of the on-chip peripherals is given in Table 41. The MCU is placed under the following conditions: • All I/O pins are in Analog mode • The given value is calculated by measuring the difference of the current consumptions: – when the peripheral is clocked on – when the peripheral is clocked off • Ambient operating temperature and supply voltage conditions summarized in Table 20: Voltage characteristics • The power consumption of the digital part of the on-chip peripherals is given in Table 41. The power consumption of the analog part of the peripherals (where applicable) is indicated in each related section of the datasheet. Table 41. Peripheral current consumption Range 1 Range 2 Low-power run and sleep Bus Matrix(1) 3.2 2.9 3.1 ADC independent clock domain 0.4 0.1 0.2 ADC clock domain 2.1 1.9 1.9 CRC 0.4 0.2 0.3 DMA1 1.4 1.3 1.4 DMA2 1.5 1.3 1.4 6.2 5.2 5.8 1.7 1.4 1.6 Peripheral FLASH (2) GPIOA GPIOB(2)) AHB APB1 112/207 1.6 1.3 1.6 (2) GPIOC 1.7 1.5 1.6 GPIOD(2) 1.8 1.6 1.7 (2) GPIOE 1.7 1.6 1.6 GPIOH(2) 0.6 0.6 0.5 QSPI 7.0 5.8 7.3 RNG independent clock domain 2.2 N/A N/A RNG clock domain 0.5 N/A N/A SRAM1 0.8 0.9 0.7 SRAM2 1.0 0.8 0.8 TSC 1.6 1.3 1.3 All AHB Peripherals 25.2 21.7 23.6 AHB to APB1 bridge(3) 0.9 0.7 0.9 CAN1 4.1 3.2 3.9 DAC1 2.4 1.8 2.2 DS11910 Rev 5 Unit µA/MHz STM32L451xx Electrical characteristics Table 41. Peripheral current consumption (continued) Range 1 Range 2 Low-power run and sleep RTCA 1.7 1.1 2.1 CRS 0.3 0.3 0.6 I2C1 independent clock domain 3.5 2.8 3.4 I2C1 clock domain 1.1 0.9 1.0 I2C2 independent clock domain 3.5 3.0 3.4 I2C2 clock domain 1.1 0.7 0.9 I2C3 independent clock domain 2.9 2.3 2.5 I2C3 clock domain 0.9 0.4 0.8 LPUART1 independent clock domain 1.9 1.6 1.8 LPUART1 clock domain 0.6 0.6 0.6 LPTIM1 independent clock domain 2.9 2.4 2.8 LPTIM1 clock domain 0.8 0.4 0.7 LPTIM2 independent clock domain 3.1 2.7 3.9 LPTIM2 clock domain 0.8 0.7 0.8 OPAMP 0.4 0.2 0.4 PWR 0.4 0.1 0.4 SPI2 1.8 1.6 1.6 SPI3 1.7 1.3 1.6 TIM2 6.2 5.0 5.9 TIM6 1.0 0.6 0.9 USART2 independent clock domain 4.1 3.6 3.8 USART2 clock domain 1.3 0.9 1.1 USART3 independent clock domain 4.3 3.5 4.2 USART3 clock domain 1.5 1.1 1.3 WWDG 0.5 0.5 0.5 All APB1 on 51.5 35.5 48.6 Peripheral APB1 DS11910 Rev 5 Unit µA/MHz 113/207 179 Electrical characteristics STM32L451xx Table 41. Peripheral current consumption (continued) Range 1 Range 2 Low-power run and sleep AHB to APB2(4) 1.0 0.9 0.9 FW 0.2 0.2 0.2 SAI1 independent clock domain 2.3 1.8 1.9 SAI1 clock domain 2.1 1.8 2.0 SDMMC1 independent clock domain 4.7 3.9 3.9 SDMMC1 clock domain 2.5 1.9 1.9 SPI1 1.8 1.6 1.7 SYSCFG/VREFBUF/COMP 0.6 0.5 0.6 TIM1 8.1 6.5 7.6 TIM15 3.7 3.0 3.4 TIM16 2.7 2.1 2.6 USART1 independent clock domain 4.8 4.2 4.6 USART1 clock domain 1.5 1.3 1.7 All APB2 on 24.2 19.9 22.6 100.9 77.1 94.8 Peripheral APB2 ALL Unit µA/MHz 1. The BusMatrix is automatically active when at least one master is ON (CPU, DMA). 2. The GPIOx (x= A…H) dynamic current consumption is approximately divided by a factor two versus this table values when the GPIO port is locked thanks to LCKK and LCKy bits in the GPIOx_LCKR register. In order to save the full GPIOx current consumption, the GPIOx clock should be disabled in the RCC when all port I/Os are used in alternate function or analog mode (clock is only required to read or write into GPIO registers, and is not used in AF or analog modes). 3. The AHB to APB1 Bridge is automatically active when at least one peripheral is ON on the APB1. 4. The AHB to APB2 Bridge is automatically active when at least one peripheral is ON on the APB2. 6.3.6 Wakeup time from low-power modes and voltage scaling transition times The wakeup times given in Table 42 are the latency between the event and the execution of the first user instruction. The device goes in low-power mode after the WFE (Wait For Event) instruction. Table 42. Low-power mode wakeup timings(1) Symbol tWUSLEEP Parameter Conditions Typ Max - 6 6 Wakeup time from Sleep mode to Run mode Wakeup time from LowWakeup in Flash with Flash in power-down tWULPSLEEP power sleep mode to Low- during low-power sleep mode (SLEEP_PD=1 power run mode in FLASH_ACR) and with clock MSI = 2 MHz 114/207 DS11910 Rev 5 6 9 Unit Nb of CPU cycles STM32L451xx Electrical characteristics Table 42. Low-power mode wakeup timings(1) (continued) Symbol Parameter Conditions Range 1 Wake up time from Stop 0 mode to Run mode in Flash Range 2 tWUSTOP0 Range 1 Wake up time from Stop 0 mode to Run mode in SRAM1 Range 2 Range 1 Wake up time from Stop 1 mode to Run in Flash Range 1 tWUSTOP1 Wake up time from Stop 1 mode to Low-power run mode in Flash Wake up time from Stop 1 mode to Low-power run mode in SRAM1 Max Wakeup clock MSI = 48 MHz 3.34 4.3 Wakeup clock HSI16 = 16 MHz 3.7 6.5 Wakeup clock MSI = 24 MHz 3.8 7.1 Wakeup clock HSI16 = 16 MHz 3.7 6.5 Wakeup clock MSI = 4 MHz 9.3 7.1 Wakeup clock MSI = 48 MHz 1.85 2.7 Wakeup clock HSI16 = 16 MHz 2.68 3 Wakeup clock MSI = 24 MHz 2.47 3.4 Wakeup clock HSI16 = 16 MHz 2.68 3 Wakeup clock MSI = 4 MHz 9.67 12.5 Wakeup clock MSI = 48 MHz 6.75 7.6 Wakeup clock HSI16 = 16 MHz 7.14 8 7 7.82 Wakeup clock HSI16 = 16 MHz 7.14 7.9 Wakeup clock MSI = 4 MHz 10.44 11.9 Wakeup clock MSI = 48 MHz 5.21 5.9 Wakeup clock HSI16 = 16 MHz 6.23 6.9 Wakeup clock MSI = 24 MHz 5.73 6.4 Wakeup clock HSI16 = 16 MHz 6.23 6.9 Wakeup clock MSI = 4 MHz 10.9 12.3 16.05 19.2 17.06 20.3 Wakeup clock MSI = 24 MHz Range 2 Wake up time from Stop 1 mode to Run mode in SRAM1 Typ Range 2 Regulator in low-power Wakeup clock MSI = 2 MHz mode (LPR=1 in PWR_CR1) DS11910 Rev 5 Unit µs µs 115/207 179 Electrical characteristics STM32L451xx Table 42. Low-power mode wakeup timings(1) (continued) Symbol Parameter Conditions Typ Max Wakeup clock MSI = 48 MHz 7.93 9.1 Wakeup clock HSI16 = 16 MHz 7.32 8.5 Wakeup clock MSI = 24 MHz 8.25 9.4 Wakeup clock HSI16 = 16 MHz 7.32 8.4 Wakeup clock MSI = 4 MHz 11.43 13.3 Wakeup clock MSI = 48 MHz 5.23 6 Wakeup clock HSI16 = 16 MHz 6.33 7.1 Wakeup clock MSI = 24 MHz 5.78 6.5 Wakeup clock HSI16 = 16 MHz 6.33 7.1 Wakeup clock MSI = 4 MHz 11.37 12.9 Wakeup time from Standby Range 1 mode to Run mode Wakeup clock MSI = 8 MHz 16.13 18.2 Wakeup clock MSI = 4 MHz 24.06 26.6 Wakeup time from Standby Range 1 with SRAM2 to Run mode Wakeup clock MSI = 8 MHz 16.09 18.2 Wakeup clock MSI = 4 MHz 24 26.6 Range 1 Wake up time from Stop 2 mode to Run mode in Flash Range 2 tWUSTOP2 Range 1 Wake up time from Stop 2 mode to Run mode in SRAM1 tWUSTBY tWUSTBY SRAM2 tWUSHDN Wakeup time from Shutdown mode to Run mode Range 2 Range 1 Wakeup clock MSI = 4 MHz 255.38 316.41 Unit µs µs µs µs 1. Guaranteed by characterization results. Table 43. Regulator modes transition times(1) Symbol tWULPRUN tVOST Parameter Conditions Typ Max Wakeup time from Low-power run mode to Code run with MSI 2 MHz Run mode(2) 5 7 Regulator transition time from Range 2 to Range 1 or Range 1 to Range 2(3) 20 40 Typ Max Stop 0 mode - 1.7 Stop 1 mode and Stop 2 mode - 8.5 Code run with MSI 24 MHz Unit µs 1. Guaranteed by characterization results. 2. Time until REGLPF flag is cleared in PWR_SR2. 3. Time until VOSF flag is cleared in PWR_SR2. Table 44. Wakeup time using USART/LPUART(1) Symbol tWUUSART tWULPUART Parameter Conditions Wakeup time needed to calculate the maximum USART/LPUART baudrate permitting to wakeup up from stop mode when USART/LPUART clock source is HSI16 1. Guaranteed by design. 116/207 DS11910 Rev 5 Unit µs STM32L451xx 6.3.7 Electrical characteristics External clock source characteristics High-speed external user clock generated from an external source In bypass mode the HSE oscillator is switched off and the input pin is a standard GPIO. The external clock signal has to respect the I/O characteristics in Section 6.3.14. However, the recommended clock input waveform is shown in Figure 19: High-speed external clock source AC timing diagram. Table 45. High-speed external user clock characteristics(1) Symbol fHSE_ext Parameter User external clock source frequency Conditions Min Typ Max Voltage scaling Range 1 - 8 48 Voltage scaling Range 2 - 8 26 Unit MHz VHSEH OSC_IN input pin high level voltage - 0.7 VDDIOx - VDDIOx VHSEL OSC_IN input pin low level voltage - VSS - 0.3 VDDIOx Voltage scaling Range 1 7 - - Voltage scaling Range 2 18 tw(HSEH) OSC_IN high or low time tw(HSEL) V ns - - 1. Guaranteed by design. Figure 19. High-speed external clock source AC timing diagram tw(HSEH) VHSEH 90% VHSEL 10% tr(HSE) tf(HSE) tw(HSEL) t THSE MS19214V2 DS11910 Rev 5 117/207 179 Electrical characteristics STM32L451xx Low-speed external user clock generated from an external source In bypass mode the LSE oscillator is switched off and the input pin is a standard GPIO. The external clock signal has to respect the I/O characteristics in Section 6.3.14. However, the recommended clock input waveform is shown in Figure 20. Table 46. Low-speed external user clock characteristics(1) Symbol Parameter Conditions Min Typ Max Unit kHz fLSE_ext User external clock source frequency - - 32.768 1000 VLSEH OSC32_IN input pin high level voltage - 0.7 VDDIOx - VDDIOx VLSEL OSC32_IN input pin low level voltage - VSS - 0.3 VDDIOx - 250 - - tw(LSEH) OSC32_IN high or low time tw(LSEL) V ns 1. Guaranteed by design. Figure 20. Low-speed external clock source AC timing diagram tw(LSEH) VLSEH 90% VLSEL 10% tr(LSE) tf(LSE) t tw(LSEL) TLSE MS19215V2 118/207 DS11910 Rev 5 STM32L451xx Electrical characteristics High-speed external clock generated from a crystal/ceramic resonator The high-speed external (HSE) clock can be supplied with a 4 to 48 MHz crystal/ceramic resonator oscillator. All the information given in this paragraph are based on design simulation results obtained with typical external components specified in Table 47. In the application, the resonator and the load capacitors have to be placed as close as possible to the oscillator pins in order to minimize output distortion and startup stabilization time. Refer to the crystal resonator manufacturer for more details on the resonator characteristics (frequency, package, accuracy). Table 47. HSE oscillator characteristics(1) Symbol fOSC_IN RF Conditions(2) Min Typ Max Unit Oscillator frequency - 4 8 48 MHz Feedback resistor - - 200 - kΩ - - 5.5 VDD = 3 V, Rm = 30 Ω, CL = 10 pF@8 MHz - 0.44 - VDD = 3 V, Rm = 45 Ω, CL = 10 pF@8 MHz - 0.45 - VDD = 3 V, Rm = 30 Ω, CL = 5 pF@48 MHz - 0.68 - VDD = 3 V, Rm = 30 Ω, CL = 10 pF@48 MHz - 0.94 - VDD = 3 V, Rm = 30 Ω, CL = 20 pF@48 MHz - 1.77 - Startup - - 1.5 mA/V VDD is stabilized - 2 - ms Parameter (3) During startup IDD(HSE) Gm HSE current consumption Maximum critical crystal transconductance tSU(HSE)(4) Startup time mA 1. Guaranteed by design. 2. Resonator characteristics given by the crystal/ceramic resonator manufacturer. 3. This consumption level occurs during the first 2/3 of the tSU(HSE) startup time 4. tSU(HSE) is the startup time measured from the moment it is enabled (by software) to a stabilized 8 MHz oscillation is reached. This value is measured for a standard crystal resonator and it can vary significantly with the crystal manufacturer For CL1 and CL2, it is recommended to use high-quality external ceramic capacitors in the 5 pF to 20 pF range (typ.), designed for high-frequency applications, and selected to match the requirements of the crystal or resonator (see Figure 21). CL1 and CL2 are usually the same size. The crystal manufacturer typically specifies a load capacitance which is the series combination of CL1 and CL2. PCB and MCU pin capacitance must be included (10 pF can be used as a rough estimate of the combined pin and board capacitance) when sizing CL1 and CL2. DS11910 Rev 5 119/207 179 Electrical characteristics Note: STM32L451xx For information on selecting the crystal, refer to the application note AN2867 “Oscillator design guide for ST microcontrollers” available from the ST website www.st.com. Figure 21. Typical application with an 8 MHz crystal Resonator with integrated capacitors CL1 OSC_IN 8 MHz resonator CL2 REXT (1) fHSE RF Bias controlled gain OSC_OUT MS19876V1 1. REXT value depends on the crystal characteristics. Low-speed external clock generated from a crystal resonator The low-speed external (LSE) clock can be supplied with a 32.768 kHz crystal resonator oscillator. All the information given in this paragraph are based on design simulation results obtained with typical external components specified in Table 48. In the application, the resonator and the load capacitors have to be placed as close as possible to the oscillator pins in order to minimize output distortion and startup stabilization time. Refer to the crystal resonator manufacturer for more details on the resonator characteristics (frequency, package, accuracy). Table 48. LSE oscillator characteristics (fLSE = 32.768 kHz)(1) Symbol IDD(LSE) Parameter LSE current consumption Maximum critical crystal Gmcritmax gm tSU(LSE)(3) Startup time 120/207 Conditions(2) Min Typ Max LSEDRV[1:0] = 00 Low drive capability - 250 - LSEDRV[1:0] = 01 Medium low drive capability - 315 - LSEDRV[1:0] = 10 Medium high drive capability - 500 - LSEDRV[1:0] = 11 High drive capability - 630 - LSEDRV[1:0] = 00 Low drive capability - - 0.5 LSEDRV[1:0] = 01 Medium low drive capability - - 0.75 LSEDRV[1:0] = 10 Medium high drive capability - - 1.7 LSEDRV[1:0] = 11 High drive capability - - 2.7 VDD is stabilized - 2 - DS11910 Rev 5 Unit nA µA/V s STM32L451xx Electrical characteristics 1. Guaranteed by design. 2. Refer to the note and caution paragraphs below the table, and to the application note AN2867 “Oscillator design guide for ST microcontrollers”. 3. tSU(LSE) is the startup time measured from the moment it is enabled (by software) to a stabilized 32.768 kHz oscillation is reached. This value is measured for a standard crystal and it can vary significantly with the crystal manufacturer Note: For information on selecting the crystal, refer to the application note AN2867 “Oscillator design guide for ST microcontrollers” available from the ST website www.st.com. Figure 22. Typical application with a 32.768 kHz crystal Resonator with integrated capacitors CL1 OSC32_IN fLSE Drive programmable amplifier 32.768 kHz resonator OSC32_OUT CL2 MS30253V2 Note: An external resistor is not required between OSC32_IN and OSC32_OUT and it is forbidden to add one. DS11910 Rev 5 121/207 179 Electrical characteristics 6.3.8 STM32L451xx Internal clock source characteristics The parameters given in Table 49 are derived from tests performed under ambient temperature and supply voltage conditions summarized in Table 23: General operating conditions. The provided curves are characterization results, not tested in production. High-speed internal (HSI16) RC oscillator Table 49. HSI16 oscillator characteristics(1) Symbol fHSI16 TRIM Parameter HSI16 Frequency HSI16 user trimming step DuCy(HSI16)(2) Duty Cycle Conditions Min Typ Max Unit 15.88 - 16.08 MHz Trimming code is not a multiple of 64 0.2 0.3 0.4 Trimming code is a multiple of 64 -4 -6 -8 45 - 55 % -1 - 1 % -2 - 1.5 % -0.1 - 0.05 % VDD=3.0 V, TA=30 °C - % ∆Temp(HSI16) HSI16 oscillator frequency TA= 0 to 85 °C drift over temperature TA= -40 to 125 °C ∆VDD(HSI16) HSI16 oscillator frequency VDD=1.62 V to 3.6 V drift over VDD tsu(HSI16)(2) HSI16 oscillator start-up time - - 0.8 1.2 μs tstab(HSI16)(2) HSI16 oscillator stabilization time - - 3 5 μs IDD(HSI16)(2) HSI16 oscillator power consumption - - 155 190 μA 1. Guaranteed by characterization results. 2. Guaranteed by design. 122/207 DS11910 Rev 5 STM32L451xx Electrical characteristics Figure 23. HSI16 frequency versus temperature MHz 16.4 +2% 16.3 +1.5% 16.2 +1% 16.1 16 15.9 -1% 15.8 -1.5% 15.7 -2% 15.6 -40 -20 0 20 min 40 mean 60 80 100 120 °C max MSv39299V1 DS11910 Rev 5 123/207 179 Electrical characteristics STM32L451xx Multi-speed internal (MSI) RC oscillator Table 50. MSI oscillator characteristics(1) Symbol Parameter Conditions MSI mode fMSI ∆TEMP(MSI)(2) 124/207 MSI frequency after factory calibration, done at VDD=3 V and TA=30 °C MSI oscillator frequency drift over temperature Min Typ Max Range 0 98.7 100 101.3 Range 1 197.4 200 202.6 Range 2 394.8 400 405.2 Range 3 789.6 800 810.4 Range 4 0.987 1 1.013 Range 5 1.974 2 2.026 Range 6 3.948 4 4.052 Range 7 7.896 8 8.104 Range 8 15.79 16 16.21 Range 9 23.69 24 24.31 Range 10 31.58 32 32.42 Range 11 47.38 48 48.62 Range 0 - 98.304 - Range 1 - 196.608 - Range 2 - 393.216 - Range 3 - 786.432 - Range 4 - 1.016 - PLL mode Range 5 XTAL= 32.768 kHz Range 6 - 1.999 - - 3.998 - Range 7 - 7.995 - Range 8 - 15.991 - Range 9 - 23.986 - Range 10 - 32.014 - Range 11 - 48.005 - -3.5 - 3 -8 - 6 MSI mode TA= -0 to 85 °C TA= -40 to 125 °C DS11910 Rev 5 Unit kHz MHz kHz MHz % STM32L451xx Electrical characteristics Table 50. MSI oscillator characteristics(1) (continued) Symbol Parameter Conditions Min Typ VDD=1.62 V to 3.6 V -1.2 - VDD=2.4 V to 3.6 V -0.5 - VDD=1.62 V to 3.6 V -2.5 - VDD=2.4 V to 3.6 V -0.8 - VDD=1.62 V to 3.6 V -5 - VDD=2.4 V to 3.6 V -1.6 - TA= -40 to 85 °C - 1 2 TA= -40 to 125 °C - 2 4 Range 0 to 3 ∆VDD(MSI)(2) MSI oscillator frequency drift MSI mode over VDD (reference is 3 V) Range 4 to 7 Range 8 to 11 ∆FSAMPLING (MSI)(2)(4) CC jitter(MSI)(4) P jitter(MSI)(4) tSU(MSI)(4) tSTAB(MSI)(4) Frequency MSI mode variation in sampling mode(3) Max Unit 0.5 0.7 % 1.2 % RMS cycle-tocycle jitter PLL mode Range 11 - - 60 - ps RMS Period jitter PLL mode Range 11 - - 50 - ps Range 0 - - 10 20 Range 1 - - 5 10 Range 2 - - 4 8 Range 3 - - 3 7 Range 4 to 7 - - 3 6 Range 8 to 11 - - 2.5 6 10 % of final frequency - - 0.25 0.5 5 % of final frequency - - 0.5 1.25 1 % of final frequency - - - 2.5 MSI oscillator start-up time MSI oscillator stabilization time PLL mode Range 11 DS11910 Rev 5 us ms 125/207 179 Electrical characteristics STM32L451xx Table 50. MSI oscillator characteristics(1) (continued) Symbol IDD(MSI)(4) Parameter MSI oscillator power consumption Conditions MSI and PLL mode Min Typ Max Range 0 - - 0.6 1 Range 1 - - 0.8 1.2 Range 2 - - 1.2 1.7 Range 3 - - 1.9 2.5 Range 4 - - 4.7 6 Range 5 - - 6.5 9 Range 6 - - 11 15 Range 7 - - 18.5 25 Range 8 - - 62 80 Range 9 - - 85 110 Range 10 - - 110 130 Range 11 - - 155 190 1. Guaranteed by characterization results. 2. This is a deviation for an individual part once the initial frequency has been measured. 3. Sampling mode means Low-power run/Low-power sleep modes with Temperature sensor disable. 4. Guaranteed by design. Figure 24. Typical current consumption versus MSI frequency 126/207 DS11910 Rev 5 Unit µA STM32L451xx Electrical characteristics High-speed internal 48 MHz (HSI48) RC oscillator Table 51. HSI48 oscillator characteristics(1) Symbol fHSI48 TRIM USER TRIM COVERAGE Parameter Conditions HSI48 Frequency VDD=3.0V, TA=30°C HSI48 user trimming step - HSI48 user trimming coverage ±32 steps DuCy(HSI48) Duty Cycle - DVDD(HSI48) HSI48 oscillator frequency drift with VDD Typ Max Unit - 48 - MHz - 0.11 (2) 0.18 (2) % ±3(3) ±3.5(3) - % 45(2) - 55(2) % - - ±3(3) VDD = 3.0 V to 3.6 V, TA = –15 to 85 °C Accuracy of the HSI48 oscillator ACCHSI48_REL over temperature (factory calibrated) Min % VDD = 1.65 V to 3.6 V, TA = –40 to 125 °C - - VDD = 3 V to 3.6 V - 0.025(3) 0.05(3) VDD = 1.65 V to 3.6 V - 0.05(3) 0.1(3) (3) ±4.5 % tsu(HSI48) HSI48 oscillator start-up time - - 2.5(2) 6(2) μs IDD(HSI48) HSI48 oscillator power consumption - - 340(2) 380(2) μA NT jitter Next transition jitter Accumulated jitter on 28 cycles(4) - - +/-0.15(2) - ns PT jitter Paired transition jitter Accumulated jitter on 56 cycles(4) - - +/-0.25(2) - ns 1. VDD = 3 V, TA = –40 to 125°C unless otherwise specified. 2. Guaranteed by design. 3. Guaranteed by characterization results. 4. Jitter measurement are performed without clock source activated in parallel. DS11910 Rev 5 127/207 179 Electrical characteristics STM32L451xx Figure 25. HSI48 frequency versus temperature % 6 4 2 0 -2 -4 -6 -50 -30 -10 10 Avg 30 50 70 90 min 110 130 °C max MSv40989V1 Low-speed internal (LSI) RC oscillator Table 52. LSI oscillator characteristics(1) Symbol Parameter LSI Frequency fLSI Min Typ Max VDD = 3.0 V, TA = 30 °C 31.04 - 32.96 VDD = 1.62 to 3.6 V, TA = -40 to 125 °C 29.5 - 34 - - 80 130 μs 5% of final frequency - 125 180 μs - - 110 180 nA LSI oscillator startup time tSU(LSI)(2) tSTAB(LSI)(2) IDD(LSI)(2) Conditions LSI oscillator stabilization time LSI oscillator power consumption Unit kHz 1. Guaranteed by characterization results. 2. Guaranteed by design. 6.3.9 PLL characteristics The parameters given in Table 53 are derived from tests performed under temperature and VDD supply voltage conditions summarized in Table 23: General operating conditions. Table 53. PLL, PLLSAI1 characteristics(1) Symbol fPLL_IN 128/207 Parameter Conditions Min Typ Max Unit PLL input clock(2) - 4 - 16 MHz PLL input clock duty cycle - 45 - 55 % DS11910 Rev 5 STM32L451xx Electrical characteristics Table 53. PLL, PLLSAI1 characteristics(1) (continued) Symbol Parameter fPLL_P_OUT PLL multiplier output clock P fPLL_Q_OUT PLL multiplier output clock Q fPLL_R_OUT PLL multiplier output clock R fVCO_OUT tLOCK Jitter IDD(PLL) PLL VCO output Conditions Min Typ Max Voltage scaling Range 1 3.0968 - 80 Voltage scaling Range 2 3.0968 - 26 Voltage scaling Range 1 12 - 80 Voltage scaling Range 2 12 - 26 Voltage scaling Range 1 12 - 80 Voltage scaling Range 2 12 - 26 Voltage scaling Range 1 96 - 344 Voltage scaling Range 2 96 - 128 - 15 40 - 40 - - 30 - VCO freq = 96 MHz - 200 260 VCO freq = 192 MHz - 300 380 VCO freq = 344 MHz - 520 650 PLL lock time RMS cycle-to-cycle jitter RMS period jitter PLL power consumption on VDD(1) System clock 80 MHz Unit MHz MHz MHz MHz μs ±ps μA 1. Guaranteed by design. 2. Take care of using the appropriate division factor M to obtain the specified PLL input clock values. The M factor is shared between the 2 PLLs. DS11910 Rev 5 129/207 179 Electrical characteristics 6.3.10 STM32L451xx Flash memory characteristics Table 54. Flash memory characteristics(1) Symbol Parameter Conditions Typ Max Unit tprog 64-bit programming time - 81.69 90.76 µs tprog_row one row (32 double word) programming time normal programming 2.61 2.90 fast programming 1.91 2.12 tprog_page one page (2 Kbyte) programming time normal programming 20.91 23.24 fast programming 15.29 16.98 22.02 24.47 normal programming 5.35 5.95 fast programming 3.91 4.35 22.13 24.59 Write mode 3.4 - Erase mode 3.4 - Write mode 7 (for 2 μs) - Erase mode 7 (for 41 μs) - tERASE tprog_bank tME IDD Page (2 KB) erase time one bank (512 Kbyte) programming time - Mass erase time (one or two banks) - Average consumption from VDD Maximum current (peak) ms s ms mA 1. Guaranteed by design. Table 55. Flash memory endurance and data retention Symbol NEND tRET Min(1) Unit TA = –40 to +105 °C 10 kcycles 1 kcycle(2) at TA = 85 °C 30 Parameter Endurance Data retention Conditions 1 kcycle (2) 1 kcycle (2) at TA = 105 °C 15 at TA = 125 °C 7 (2) at TA = 55 °C 30 10 kcycles(2) at TA = 85 °C 15 10 kcycles 10 kcycles (2) at TA = 105 °C 1. Guaranteed by characterization results. 2. Cycling performed over the whole temperature range. 130/207 DS11910 Rev 5 10 Years STM32L451xx 6.3.11 Electrical characteristics EMC characteristics Susceptibility tests are performed on a sample basis during device characterization. Functional EMS (electromagnetic susceptibility) While a simple application is executed on the device (toggling 2 LEDs through I/O ports). the device is stressed by two electromagnetic events until a failure occurs. The failure is indicated by the LEDs: • Electrostatic discharge (ESD) (positive and negative) is applied to all device pins until a functional disturbance occurs. This test is compliant with the IEC 61000-4-2 standard. • FTB: A Burst of Fast Transient voltage (positive and negative) is applied to VDD and VSS through a 100 pF capacitor, until a functional disturbance occurs. This test is compliant with the IEC 61000-4-4 standard. A device reset allows normal operations to be resumed. The test results are given in Table 56. They are based on the EMS levels and classes defined in application note AN1709. Table 56. EMS characteristics Conditions Level/ Class Symbol Parameter VFESD Voltage limits to be applied on any I/O pin to induce a functional disturbance VDD = 3.3 V, TA = +25 °C, fHCLK = 80 MHz, conforming to IEC 61000-4-2 3B VEFTB Fast transient voltage burst limits to be applied through 100 pF on VDD and VSS pins to induce a functional disturbance VDD = 3.3 V, TA = +25 °C, fHCLK = 80 MHz, conforming to IEC 61000-4-4 5A Designing hardened software to avoid noise problems EMC characterization and optimization are performed at component level with a typical application environment and simplified MCU software. It should be noted that good EMC performance is highly dependent on the user application and the software in particular. Therefore it is recommended that the user applies EMC software optimization and prequalification tests in relation with the EMC level requested for his application. Software recommendations The software flowchart must include the management of runaway conditions such as: • Corrupted program counter • Unexpected reset • Critical Data corruption (control registers...) DS11910 Rev 5 131/207 179 Electrical characteristics STM32L451xx Prequalification trials Most of the common failures (unexpected reset and program counter corruption) can be reproduced by manually forcing a low state on the NRST pin or the Oscillator pins for 1 second. To complete these trials, ESD stress can be applied directly on the device, over the range of specification values. When unexpected behavior is detected, the software can be hardened to prevent unrecoverable errors occurring (see application note AN1015). Electromagnetic Interference (EMI) The electromagnetic field emitted by the device are monitored while a simple application is executed (toggling 2 LEDs through the I/O ports). This emission test is compliant with IEC 61967-2 standard which specifies the test board and the pin loading. Table 57. EMI characteristics Symbol Parameter Max vs. [fHSE/fHCLK] Monitored frequency band Conditions Unit 8 MHz/ 80 MHz SEMI Peak level 0.1 MHz to 30 MHz -8 VDD = 3.6 V, TA = 25 °C, 30 MHz to 130 MHz LQFP100 package 130 MHz to 1 GHz compliant with IEC 61967-2 1 GHz to 2 GHz 2 8 EMI Level 6.3.12 dBµV 5 2.5 - Electrical sensitivity characteristics Based on three different tests (ESD, LU) using specific measurement methods, the device is stressed in order to determine its performance in terms of electrical sensitivity. Electrostatic discharge (ESD) Electrostatic discharges (a positive then a negative pulse separated by 1 second) are applied to the pins of each sample according to each pin combination. The sample size depends on the number of supply pins in the device (3 parts × (n+1) supply pins). This test conforms to the ANSI/JEDEC standard. Table 58. ESD absolute maximum ratings Symbol VESD(HBM) Ratings Conditions TA = +25 °C, conforming Electrostatic discharge to ANSI/ESDA/JEDEC voltage (human body model) JS-001 Electrostatic discharge VESD(CDM) voltage (charge device model) TA = +25 °C, conforming to ANSI/ESD STM5.3.1 1. Guaranteed by characterization results. 132/207 DS11910 Rev 5 Class Maximum value(1) 2 2000 Unit V C3 250 STM32L451xx Electrical characteristics Static latch-up Two complementary static tests are required on six parts to assess the latch-up performance: • A supply overvoltage is applied to each power supply pin. • A current injection is applied to each input, output and configurable I/O pin. These tests are compliant with EIA/JESD 78A IC latch-up standard. Table 59. Electrical sensitivities Symbol LU 6.3.13 Parameter Static latch-up class Conditions Class TA = +105 °C conforming to JESD78A II I/O current injection characteristics As a general rule, current injection to the I/O pins, due to external voltage below VSS or above VDDIOx (for standard, 3.3 V-capable I/O pins) should be avoided during normal product operation. However, in order to give an indication of the robustness of the microcontroller in cases when abnormal injection accidentally happens, susceptibility tests are performed on a sample basis during device characterization. Functional susceptibility to I/O current injection While a simple application is executed on the device, the device is stressed by injecting current into the I/O pins programmed in floating input mode. While current is injected into the I/O pin, one at a time, the device is checked for functional failures. The failure is indicated by an out of range parameter: ADC error above a certain limit (higher than 5 LSB TUE), out of conventional limits of induced leakage current on adjacent pins (out of the -5 µA/+0 µA range) or other functional failure (for example reset occurrence or oscillator frequency deviation). The characterization results are given in Table 60. Negative induced leakage current is caused by negative injection and positive induced leakage current is caused by positive injection. Table 60. I/O current injection susceptibility(1) Functional susceptibility Symbol IINJ Description Unit Negative injection Positive injection Injected current on all pins except PA4, PA5, PE8, PE9, PE10, PE11, PE12 -5 N/A(2) Injected current on PE8, PE9, PE10, PE11, PE12 -0 N/A(2) Injected current on PA4, PA5 pins -5 0 mA 1. Guaranteed by characterization results. 2. Injection is not possible. DS11910 Rev 5 133/207 179 Electrical characteristics 6.3.14 STM32L451xx I/O port characteristics General input/output characteristics Unless otherwise specified, the parameters given in Table 61 are derived from tests performed under the conditions summarized in Table 23: General operating conditions. All I/Os are designed as CMOS- and TTL-compliant. Table 61. I/O static characteristics Symbol VIL(1) VIH(1) Vhys(3) Parameter Conditions Min Typ Max I/O input low level voltage 1.62 V