# Release Notes for

# STM32L4xx CMSIS

Copyright © 2017 STMicroelectronics

# Purpose

This driver provides the CMSIS device for the stm32l4xx products. This covers

- STM32L412xx/STM32L422x devices
- STM32L431xx/STM32L432xx/STM32L433xx/STM32L442xx/ STM32L443xx devices
- STM32L451xx/STM32L452xx/STM32L462xx devices
- STM32L471xx/STM32L475xx/STM32L476xx/STM32L485xx/ STM32L486xx devices
- STM32L496xx/STM32L4A6xx devices
- STM32L4P5xx/STM32L4Q5xx devices
- STM32L4R5xx/STM32L4R7xx/STM32L4R9xx/STM32L4S5xx/ STM32L4S7xx and STM32L4S9xx devices

This driver is composed of the descriptions of the registers under “Include” directory.

Various template file are provided to easily build an application. They can be adapted to fit applications requirements.

- Templates/system_stm32l4xx.c contains the initialization code referred as SystemInit.
- Startup files are provided as example for IAR©, KEIL© and STM32CubeIDE©.
- Linker files are provided as example for IAR©, KEIL© and STM32CubeIDE©.

# Update History

V1.7.5 / 14-November-2025

## Main Changes

- Allow redefinition of the macro ‘VECT_TAB_OFFSET’ externally from the IDE, makefile, or command line.
- Fix Capture Compare register TIMx_CCR5 defintion.

V1.7.4 / 28-June-2024

## Main Changes

- Remove cast (uint32_t) from FLASH_SIZE_DATA_REGISTER define.

V1.7.3 / 07-June-2023

## Main Changes

- Remove the SDMMC_STA_STBITERR bit.

V1.7.2 / 26-November-2021

## Main Changes

- General updates to fix known defects and enhancements implementation.

- All source files: update disclaimer to add reference to the new license agreement.

- Headline
  - Add LSI maximum startup time datasheet value: LSI_STARTUP_TIME.
  - __FPU_PRESENT defined with 1U instead of 1 to avoid compilation warning
  - Improve GCC startup files robustness.
  - STM32L476xx.h header file: Add PWR SR1 EXT_SMPS_RDY bit definition for WLCSP82 package with Ext SMPS
- stm32l4xx.h
  - Add new atomic register access macros.
- system_stm32l4xx.c
  - Update SystemInit() API to don’t reset RCC registers to its reset values

V1.7.1 / 11-February-2021

## Main Changes

- stm32l431xx.h, stm32l432xx.h, stm32l433xx.h, stm32l442xx.h, stm32l443xx.h and stm32l4xxxxx.h
  - Revert correction done on HSITRIM field for STM32L43x/STM32L44x devices after update of reference manual
- stm32l412xx.h, stm32l422xx.h, stm32l431xx.h, stm32l432xx.h, stm32l433xx.h, stm32l442xx.h, stm32l443xx.h, stm32l451xx.h, stm32l452xx.h, stm32l462xx.h, stm32l496xx.h, stm32l4a6xx.h, stm32l4p5xx.h, stm32l4q5xx.h, stm32l4r5xx.h, stm32l4r7xx.h, stm32l4r9xx.h, stm32l4s5xx.h, stm32l4s7xx.h and stm32l4s9xx.h
  - Fix double macro definition of CRS_CR_TRIM in CRS_RC register
- stm32l4p5xx.h, stm32l4q5xx.h
  - Remove LTDC_Layer2 definition as STM32L4P5xx/STM32L4Q5xx devices only support one-layer LTDC
- system_stm32l4xx.c/.h
  - Update VTOR configuration to be modified by user
  - Update MISRA-C 2012 compliance

V1.7.0 / 26-June-2020

## Main Changes

- stm32l4p5xx.h, stm32l4q5xx.h, stm32l4r5xx.h, stm32l4r7xx.h, stm32l4r9xx.h, stm32l4s5xx.h, stm32l4s7xx.h, stm32l4s9xx.h and stm32l4xxxxx.h
  - Update bit definitions in OCTOSPI registers
    - Remove WRAPSIZE field in DCR2 register as the wrap is not supported for L4+ devices
    - Update DLYBYP, CSHT, TOF and SIOO bit definitions
- stm32l431xx.h, stm32l432xx.h, stm32l433xx.h, stm32l442xx.h, stm32l443xx.h and stm32l4xxxxx.h
  - Align HSITRIM configuration with reference manual
- stm32l412xx.h, stm32l422xx.h, stm32l431xx.h, stm32l432xx.h, stm32l433xx.h, stm32l442xx.h, stm32l443xx.h, stm32l451xx.h, stm32l452xx.h, stm32l462xx.h, stm32l496xx.h, stm32l4a6xx.h, stm32l4p5xx.h, stm32l4q5xx.h, stm32l4r5xx.h, stm32l4r7xx.h, stm32l4r9xx.h, stm32l4s5xx.h, stm32l4s7xx.h and stm32l4s9xx.h
  - Add bit descriptions for CRS_CR_TRIM field in CRS_RC register
- All gcc startup files
  - Align startup files with IAR/Keil startup files by calling SystemInit() before data initialization

V1.6.1 / 07-February-2020

## Main Changes

- Add bit definitions in OCTOSPI registers
  - stm32l4p5xx.h, stm32l4q5xx.h, stm32l4r5xx.h, stm32l4r7xx.h, stm32l4r9xx.h, stm32l4s5xx.h, stm32l4s7xx.h and stm32l4s9xx.h
    - Add OCTOSPI DLYBYP field definition in DCR1 register
  - stm32L4p5xx.h and stm32L4q5xx.h
    - Add OCTOSPI MAXTRAN field definition in DCR3 register

V1.6.0 / 22-November-2019

## Main Changes

- Add the support of STM32L4P5xx/STM32L4Q5xx devices
  - Add stm32l4p5xx.h and stm32l4q5xx.h device description files
  - Add startup files startup_stm32l4p5xx.s and stm32l4q5xx.s for EWARM, MDK-ARM and CubeIDE toolchains
  - Add EWARM associated linker files for execution from internal RAM or internal FLASH
  - stm32l4xx.h
    - Add the following device defines:
      - “#define STM32L4P5xx” for all STM32L4P5xx devices
      - “#define STM32L4Q5xx” for all STM32L4Q5xx devices
- All gcc startup files
  - Remove reference to Atollic IDE in comments
- stm32l412xx.h and stm32l422xx.h
  - Remove RTC_ICSR_ALRAWF and RTC_ICSR_ALRBWF bits definition (not applicable to these devices)
  - Correct RTC_WUTR_WUTOCLR_Msk definition comment
- gcc startup_stm32l412xx.s and startup_stm32l422xx.s files
  - Add missing USB_IRQHander definition
- stm32l4r5xx.h, stm32l4r7xx.h, stm32l4r9xx.h, stm32l4s5xx.h, stm32l4s7xx.h and stm32l4s9xx.h
  - Add RCC_DLYCFGR register definition
  - Swap I2C4_EV_IRQn and I2C4_ER_IRQn definitions to be aligned with startup files
- stm32l496xx.h and stm32l4a6xx.h
  - Remove PEMPTY bit definition (not applicable to these devices)
- All MDK-ARM start-up files
  - Move back the start tag of the configuration wizard to make sure STMicroelectronics copyright section doesn’t interfere with the configuration annotation parser
- All stm32l4XXxx.h device description files
  - Remove IS_TIM_SYNCHRO_INSTANCE macro

V1.5.1 / 03-April-2019

## Main Changes

- stm32l412xx.h, stm32l422xx.h, stm32l431xx.h, stm32l432xx.h, stm32l433xx.h, stm32l442xx.h, stm32l443xx.h, stm32l451xx.h, stm32l452xx.h, stm32l462xx.h and stm32l471xx.h
  - Correct comment related to PVD_PVM_IRQn definition
- stm32l412xx.h and stm32l422xx.h
  - Add missing definitions of QUADSPI DFM, FSEL and DHHC bits
  - Add missing definition of ADC_SMPR1_SMPPLUS bit
  - Correct PWR_CR3 bit name EN_ULP into ENULP
- stm32l412xx.h, stm32l422xx.h, stm32l431xx.h, stm32l432xx.h, stm32l433xx.h, stm32l442xx.h, stm32l443xx.h, stm32l451xx.h, stm32l452xx.h and stm32l462xx.h
  - Correct FLASH_PCROP1SR and FLASH_PCROP1ER registers definition
    - Correct size of PCROP fields : 16 bits for STM32L45xx/L46xx and 15 bits for STM32L43xx/L44xx
    - Correct size of page number field : 7 bits for STM32L43xx/L44xx and 6 bits STM32L41xx/L42xx
    - Correct size of WRP fields : 7 bits for STM32L43xx/L44xx
- stm32l432xx.h and stm32l442xx.h
  - Add PWR_CR2_PVME1 definition
- stm32l4r5xx.h, stm32l4r7xx.h, stm32l4r9xx.h, stm32l4s5xx.h, stm32l4s7xx.h and stm32l4s9xx.h
  - Correct SDMMC_POWER bits definition
  - Correct comments related to SDMMC_CLKCR_WIDBUS definition
  - Correct EXTI_IMR1_IM mask definition
- stm32l4xx.h
  - Correct ErrorStatus typedef

V1.5.0 / 27-July-2018

## Main Changes

- Add stm32l412xx.h and stm32l422xx.h device description files
- Add startup files startup_stm32l412xx.s and startup_stm32l422xx.s for EWARM, MDK-ARM and SW4STM32 toolchains

- Add EWARM associated linker files for execution from internal RAM or internal FLASH

- stm32l4xx.h

  - Add the following device defines:

    - "#define STM32L412xx" for all STM32L412xx devices
    - "#define STM32L422xx" for all STM32L422xx devices

- stm32l4r5xx.h, stm32l4r7xx.h, stm32l4r9xx.h, stm32l4s5xx.h, stm32l4s7xx.h and stm32l4s9xx.h description files

  - Update SDMMC mask register
  - Correct SDMMC DPSMACT and CPSMACT bits definition

- All stm32l4XXxx.h device description files except stm32l4rXxx.h and stm32l4sXxx.h

  - Correct Misra C:2012 Rule10.3 warning in replacing 0xFFUL by 0xFFU when CRC IDR register is 8-bit long only

- All iar/linker/stm32 l4XXxx_flash.icf and iar/linker/stm32 l4XXxx_sram.icf

  - Remove SRAM1 and SRAM2 (and SRAM3 for stm32 l4rXxx_flash.icf,stm32 l4sXxx_flash.icf,stm32 l4rXxx_sram.icf and stm32 l4sXxx_sram.icf) start and end addresses from ICF editor section
  - Define RAM section as covering whole SRAM1 plus SRAM2 (and SRAM3 when applicable) when the SRAM regions are contiguous

V1.4.3 / 30-April-2018

## Main Changes

- All stm32l4XXxx.h device description files

  - Fix DFSDM_FLTICR_CLRSCDF definition
  - Cleanup USB Host & Device bit definitions
  - [MISRAC2012-Rule-10.6] Use 'UL' postfix for _Msk definitions and memory/peripheral base addresses

- stm32l4r5xx.h, stm32l4r7xx.h, stm32l4r9xx.h, stm32l4s5xx.h, stm32l4s7xx.h and stm32l4s9xx.h devices description files

  - Fix SDMMC_STA_DPSMACT and SDMMC_STA_CPSMACT definitions (V1.4.1 update was incorrect)

- All stm32l4XXxx.h device description files except stm32l4r5xx.h, stm32l4r7xx.h, stm32l4r9xx.h, stm32l4s5xx.h, stm32l4s7xx.h and stm32l4s9xx.h

  - Add missing USART_CR3_UCESM bit definition

V1.4.2 / 22-December-2017

## Main Changes

- SPI_TypeDef cleanup of Reserved fields.

V1.4.1 / 6-October-2017

## Main Changes

stm32l4r5xx.h and stm32l4s5xx.h description files

- Remove LTDC peripheral definitions as LTDC not available on STM32L4R5xx/STM32L4S5xx devices

V1.4.0 / 25-August-2017

## Main Changes

- Add the support of STM32L4R5xx/STM32L4R7xx/STM32L4R9xx/STM32L4S5xx/STM32L4S7xx/STM32L4S9xx devices

  - Add stm32l4r5xx.h, stm32l4r7xx.h, stm32l4r9xx.h, stm32l4s5xx.h, stm32l4s7xx.h and stm32l4s9xx.h device description files
  - Add startup files startup_stm32l4r5xx.s, startup_stm32l4r7xx.s, startup_stm32l4r9xx.s, startup_stm32l4s5xx.s, startup_stm32l4s7xx.s and stm32l4s9xx.s for EWARM, MDK-ARM and SW4STM32 toolchains

  - Add EWARM associated linker files for execution from internal RAM or internal FLASH

  - stm32l4xx.h
    - Add the following device defines:
      - "#define STM32L4R5xx" for all STM32L4R5xx devices
      - "#define STM32L4R7xx" for all STM32L4R7xx devices
      - "#define STM32L4R9xx" for all STM32L4R9xx devices
      - "#define STM32L4S5xx" for all STM32L4S5xx devices
      - "#define STM32L4S7xx" for all STM32L4S7xx devices
      - "#define STM32L4S9xx" for all STM32L4S9xx devices

- All adequate stm32l4XXxx.h device description files

  - PWR: Rename PWR_CR3_EIWF to PWR_CR3_EIWUL
  - TIM: Add missing TIM8 check in debug macro IS_TIM_HALL_SENSOR_INTERFACE_INSTANCE() devices
  - USB: Fix USB_EP0R...USB_EP7R definitions

- system_stm32l4xx.c

  - Fix MISRA C 2004 rule 10.6 : a 'U' suffix shall be applied to all constants of 'unsigned' type

V1.3.2 / 16-June-2017

## Main Changes

- stm32l451xx.h, stm32l452xx.h, stm32l462xx.h description files

  - Remove EXTI_IMR2_IM34 and EXTI_EMR2_IM34 bits (no SWPMI EXTI line)

- stm32l432xx.h, stm32l442xx.h, stm32l452xx.h, stm32l462xx.h description files

  - Remove EXTI_IMR2_IM36 and EXTI_EMR2_IM36 bits from STM32L4x2x devices (no PVM2 EXTI line)

- stm32l431xx.h, stm32l432xx.h, stm32l442xx.h, stm32l451xx.h, stm32l452xx.h, stm32l462xx.h, stm32l471xx.h, stm32l475xx.h, stm32l485xx.h description files

  - Remove EXTI_IMR2_IM39 and EXTI_EMR2_IM39 bits from STM32L4x1x,STM32L4x2x and STM32L4x5x devices(no LCD EXTI line)

- All stm32l4XXxx.h device description files

  - Remove erroneous SRAM2_BB_BASE definition
  - Add missing EXTI_EMR2_EM constants
  - Add missing TIM8 check in debug macro IS_TIM_HALL_SENSOR_INTERFACE_INSTANCE() devices where TIM8 is present

V1.3.1 / 21-April-2017

## Main Changes

- stm32l496xx.h and stm32l4a6xx.h device description files

  - FIREWALL

    - Fix FW_VDSSA_ADD_Msk and FW_VDSL_LENG_Msk definitions

  - TIM16

    - Fix TIM16_OR1_TI1_RMP_Msk definition

V1.3.0 / 17-February-2017

## Main Changes

- Add the support of STM32L496xx/STM32L4A6xx devices

  - Add stm32l496xx.h and stm32l4a6xx.h device description files
  - Add startup files startup_stm32l496xx.s and startup_stm32l4a6xx.s for EWARM, MDK-ARM and SW4STM32 toolchains
  - Add linker files stm32l496xx_flash.icf, stm32l496xx_sram.icf, stm32l4a6xx_flash.icf and stm32l4a6xx_sram.icf used within EWARM workspaces

- stm32l4xx.h

  - Add the following device defines:

    - "#define STM32L496xx" for all STM32L496xx devices

    - "#define STM32L4A6xx" for all STM32L4A6xx devices

- All stm32l4XXxx.h device description files

  - Fix RCC_CRRCR_HSI48CAL_Pos and RCC_CRRCR_HSI48CAL values

V1.2.0 / 28-October-2016

## Main Changes

- Add the support of STM32L451xx/STM32L452xx/STM32L462xx devices

  - Add stm32l451xx.h, stm32l452xx.h and stm32l462xx.h device description files
  - Add startup files startup_stm32l451xx.s, startup_stm32l452xx.s and startup_stm32l462xx.s for EWARM, MDK-ARM and SW4STM32 toolchains
  - Add linker files stm32l451xx_flash.icf, stm32l451xx_sram.icf, stm32l452xx_flash.icf, stm32l452xx_sram.icf, stm32l462xx_flash.icf and stm32l462xx_sram.icf used within EWARM workspaces
- stm32l4xx.h
  - Add the following device defines:
  - "#define STM32L451xx" for all STM32L451xx devices
  - "#define STM32L452xx" for all STM32L452xx devices
  - "#define STM32L462xx" for all STM32L462xx devices

- All stm32l4XXxx.h device description files except stm32l451xx.h, stm32l452xx.h and stm32l462xx.h

  - Add DAC_CHANNEL2_SUPPORT definition as DAC channel 2 is present on these devices

- stm32l432xx.h and stm32l442xx.h device description files

  - Remove PWR_CR2_PVME1 and PWR_SR2_PVMO1 as VDDUSB is internally connected to VDD on these devices thus no PVM1

- stm32l475xx.h, stm32l476xx.h, stm32l485xx.h and stm32l486xx.h device description files

  - Remove USB OTG Core Id version definitions USB_OTG_CORE_ID_310A and USB_OTG_CORE_ID_320A as reserved for internal usage

V1.1.2 / 12-September-2016

## Main Changes

- Fix DAC_SR_BWST1 bit definition

- Fix SDMMC_DCTRL_DBLOCKSIZE_2 and SDMMC_DCTRL_DBLOCKSIZE_3 bits definition

- USB OTG FS

  - Add GSNPSID, GHWCFG1 and GHWCFG2 register mapping
  - Add USB OTG Core Id version definitions: USB_OTG_CORE_ID_310A and USB_OTG_CORE_ID_320A

V1.1.1 / 29-April-2016

## Main Changes

- All device register description files enriched with _Pos and _Msk defines to be used with _VAL2FLD(field, value) and _FLD2VAL(field, value) from CMSIS Core (previous defines are kept for compatibility)

- stm32l471xx.h, stm32l475xx.h, stm32l476xx.h, stm32l485xx.h and stm32l486xx.h device description files

  - Update DFSDM peripheral instance and register definitions (named DFSDM1 peripheral from now instead of DFSDM)
    - Rename DFSDMx_IRQn to DFSDM1_FLTx_IRQn for x=0,1,2 and 3 (filters)
    - Rename DFSDM channels and filters to refer to DFSDM1 peripheral instance with DFSDM1 prefix
      - DFSDM1_Channel0, DFSDM1_Channel1, ... DFSDM1_Channel7
      - DFSDM1_Filter0,DFSDM1_Filter1, ..., DFSDM1_Filter3
    - Rename registers in DFSDM_Filter_TypeDef to use FLT prefix for filter
      - FLTCR1, FLTCR2, FLTISR, FLTICR, FLTJCHGR, FLTFCR, FLTJDATAR, FLTRDATAR, FLTAWHTR, FLTAWLTR, FLTAWSR, FLTAWCFR, FLTEXMAX, FLTEXMIN, FLTCNVTIMR
    - Rename register in DFSDM_Filter_TypeDef to use CH prefix for channel
      - CHAWSCDR
    - Update RCC definitions for DFSDM1
      - Rename RCC_APB2RSTR_DFSDMRST to RCC_APB2RSTR_DFSDM1RST
      - Rename RCC_APB2ENR_DFSDMEN to RCC_APB2ENR_DFSDM1EN
      - Rename RCC_APB2SMENR_DFSDMSMEN to RCC_APB2SMENR_DFSDM1SMEN
      - Rename RCC_CCIPR_DFSDMSEL to RCC_CCIPR_DFSDM1SEL
    - Update TIM definitions for DFSDM1
      - Rename TIM1_OR2_BKDFBK0E to TIM1_OR2_BKDF1BK0E
      - Rename TIM1_OR3_BK2DFBK1E to TIM1_OR3_BK2DF1BK1E
      - Rename TIM8_OR2_BKDFBK2E to TIM8_OR2_BKDF1BK2E
      - Rename TIM8_OR3_BK2DFBK3E to TIM8_OR3_BK2DF1BK3E
      - Rename TIM15_OR2_BKDFBK0E to TIM15_OR2_BKDF1BK0E
      - Rename TIM16_OR2_BKDFBK1E to TIM16_OR2_BKDF1BK1E
      - Rename TIM17_OR2_BKDFBK2E to TIM17_OR2_BKDF1BK2E

  - FMC

    - Add FMC_BWTRx_BUSTURN register bit definition
- startup_stm32l471xx.s, startup_stm32l475xx.s, startup_stm32l476xx.s, startup_stm32l485xx.s and startup_stm32l486xx.s
  - Rename DFSDMx_IRQHandler function entry points to DFSDM1_FLTx_IRQHandler for x=0,1,2 and 3 (filters)

V1.1.0 / 26-February-2016

## Main Changes

- Add the support of STM32L431xx/STM32L432xx/STM32L433xx/STM32L442xx/STM32L443xx devices

  - Add stm32l431xx.h, stm32l432xx.h, stm32l433xx.h, stm32l442xx.h and stm32l443xx.h device description files
  - Add startup files startup_stm32l431xx.s, startup_stm32l432xx.s, startup_stm32l433xx.s, startup_stm32l442xx.s and startup_stm32l443xx.s for EWARM, MDK-ARM and SW4STM32 toolchains
  - Add linker files stm32l431xx_flash.icf, stm32l431xx_sram.icf, stm32l432xx_flash.icf, stm32l432xx_sram.icf, stm32l433xx_flash.icf, stm32l433xx_sram.icf, stm32l442xx_flash.icf, stm32l442xx_sram.icf, stm32l443xx_flash.icf and stm32l443xx_sram.icf used within EWARM workspaces
- stm32l4xx.h
  - Add the following device defines:
    - "#define STM32L431xx" for all STM32L431xx devices
    - "#define STM32L432xx" for all STM32L432xx devices
    - "#define STM32L433xx" for all STM32L433xx devices
    - "#define STM32L442xx" for all STM32L442xx devices
    - "#define STM32L443xx" for all STM32L443xx devices
- stm32l471xx.h, stm32l475xx.h, stm32l476xx.h, stm32l485xx.h and stm32l486xx.h device description files
  - DFSDM - alignment with registers & bits naming used in documentation
  - Rename DFSDM_AWSCDR_WDATA to DFSDM_CHWDATR_WDATA
  - Rename DFSDM_AWSCDR_INDAT0 to DFSDM_CHDATINR_INDAT0
  - Rename DFSDM_AWSCDR_INDAT0 to DFSDM_CHDATINR_INDAT0

V1.0.3 / 29-January-2016

## Main Changes

- stm32l471xx.h, stm32l475xx.h, stm32l476xx.h, stm32l485xx.h and stm32l486xx.h device description files

  - Apply MISRA C 2004 rule 10.6 ('U' suffix added)

  - Add PACKAGE_BASE, UID_BASE and FLASHSIZE_BASE base address definitions

  - ADC

    - Update ADC_CSR register bit definition
  - LPUART

  - Add IS_LPUART_INSTANCE() to check USART instance with low power capatibility

- system_stm32l4xx.h/.c
  - Add declaration of APB Prescaler table values (const uint8_t APBPrescTable[8])

V1.0.2 / 25-November-2015

## Main Changes

- stm32l471xx.h, stm32l475xx.h, stm32l476xx.h, stm32l485xx.h and stm32l486xx.h device description files

  - GPIO
    - Align GPIO register bit definitions with RM0351 (legacy definitions preserved for compatibility)
  - FMC
    - Remove FMC_BCR1_WFDIS bit definition (write fifo feature not available)
  - PWR
    - Stop 0 mode introduction
    - PWR_CR1_LPMS_STOP1MR renamed to PWR_CR1_LPMS_STOP0
    - PWR_CR1_LPMS_STOP1LPR renamed to PWR_CR1_LPMS_STOP1
  - RCC
    - Align RCC register bit definitions with RM0351 (legacy definitions preserved for compatibility)
  - TIM
    - Add IS_TIM_HALL_SENSOR_INTERFACE_INSTANCE() to check timer instance capability for hall sensor interface
- system_stm32l4xx.c
  - Fix PLLCFGR default value in SystemInit()

V1.0.1 / 16-September-2015

## Main Changes

- stm32l471xx.h, stm32l475xx.h, stm32l476xx.h, stm32l485xx.h and stm32l486xx.h device description files

  - DBGMCU
    - Fix DBGMCU_IDCODE_DEV_ID mask definition
  - FLASH
    - Add FLASH_OPTR_nRST_SHDW bit definition
  - I2C
    - Fix naming I2C_CR1_DNF instead of I2C_CR1_DFN
  - TIM
    - Add TIM16_OR2_BKDFBK1E bit definition
    - Add TIM17_OR2_BKDFBK2E bit definition
- system_stm32l4xx.c
  - SystemCoreClockUpdate() corrected for SystemCoreClock computation when PLL is enabled

V1.0.0 / 26-June-2015

## Main Changes

- First official release for STM32L471xx, STM32L475xx, STM32L476xx, STM32L485xx and STM32L486xx devices