ST STM32L1 Series Istruzioni per l'installazione e il funzionamento

March 2016 DocID027094 Rev 3 1/58

AN4612

Application note

Migrating from STM32L1 Series to STM32L4 Series

microcontrollers

Introduction

For designers of STM32 microcontroller applications, it is important to be able to easily

replace one microcontroller type by another one in the same product family. Migrating an

application to a different microcontroller is often needed when product requirements grow by

putting extra demands on memory size or increasing the number of I/Os. On the other hand,

cost reduction objectives are also be an argument to switch to smaller components and

shrink the PCB area.

This application note analyze the steps required to migrate an existing design from

STM32L1 Series to STM32L4 Series. It groups the most important information and lists the

vital aspects that need to be addressed.

This document lists the “full set” of features available for the STM32L1 and the equivalent

features on STM32L4 Series when available.

In order to migrate an application from STM32L1 Series to STM32L4 Series, these three

aspects need to be considered: the hardware migration, the peripheral migration and the

firmware migration.

To fully benefit from the information in this application note, the user should be familiar with

the STM32 microcontrollers documentation available on www.st.com, with focus on:

STM32L1 Series:

•STM32L1xx reference manual (RM0038)

•STM32L1xx datasheets

•STM32L1 Flash and EEPROM programming manual (PM0062)

STM32L4 Series:

•STM32L4x6 reference manual (RM0351)

•STM32L4x3 reference manual (RM0394)

•STM32L4x2 reference manual (RM0393)

•STM32L4xx datasheets.

www.st.com

Contents AN4612

2/58 DocID027094 Rev 3

Contents

1 STM32L4 Series overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2 Hardware migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3 Boot mode selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4 Peripheral migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.1 STM32 product cross-compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.2 Memory mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.3 DMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4.4 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.5 RCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4.5.1 Performance versus VCORE ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4.5.2 Peripheral access configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4.5.3 Peripheral clock configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

4.6 PWR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

4.7 RTC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

4.8 SYSCFG and RI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

4.9 GPIO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

4.10 EXTI source selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

4.11 FLASH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

4.12 U(S)ART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

4.13 I2C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

4.14 SPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

4.15 CRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

4.16 AES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

4.17 LCD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

4.18 USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

4.19 ADC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

4.20 DAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

4.21 COMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

4.22 OPAMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

DocID027094 Rev 3 3/58

AN4612 Contents

5 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

List of tables AN4612

4/58 DocID027094 Rev 3

List of tables

Table 1. Product category overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Table 2. Packages available on STM32L4xx series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 3. STM32L1 Series and STM32L4 Series pinout differences (QFP) . . . . . . . . . . . . . . . . . . . . 8

Table 4. STM32L1 Series and STM32L4 Series pinout differences (BGA) . . . . . . . . . . . . . . . . . . . . 9

Table 5. Boot modes for STM32L4 Cat. 2 devices and STM32L1 lines . . . . . . . . . . . . . . . . . . . . . . 14

Table 6. Boot modes for STM32L4 Cat. 4 devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 7. Bootloader interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Table 8. Peripheral compatibility analysis STM32L1 Series versus STM32L4 Series . . . . . . . . . . . 17

Table 9. Peripheral address mapping differences between STM32L1 Series

and STM32L4 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Table 10. DMA request differences migrating STM32L1 Series

to STM32L4 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Table 11. Interrupt vector differences between STM32L1 Series

and STM32L4 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Table 12. RCC differences between STM32L1 and STM32L4 Series . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 13. Performance versus VCORE ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 14. RCC registers used for peripheral access configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 15. PWR differences between STM32L1 Series and STM32L4 Series . . . . . . . . . . . . . . . . . . 34

Table 16. RTC differences between STM32L1 Series and STM32L4 Series. . . . . . . . . . . . . . . . . . . 37

Table 17. SYSCFG differences between STM32L1 Series and STM32L4 Series . . . . . . . . . . . . . . . 38

Table 18. EXTI differences between STM32L1 Series and STM32L4 Series . . . . . . . . . . . . . . . . . . 39

Table 19. FLASH differences between STM32L1 Series and STM32L4 Series. . . . . . . . . . . . . . . . . 40

Table 20. U(S)ART differences between STM32L1 Series and STM32L4 Series . . . . . . . . . . . . . . . 42

Table 21. I2C differences between STM32L1 Series and STM32L4 Series. . . . . . . . . . . . . . . . . . . . 44

Table 22. SPI differences between STM32L1 Series and STM32L4 Series . . . . . . . . . . . . . . . . . . . 45

Table 23. Migrating from I2S to SAI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Table 24. CRC differences between STM32L1 Series and STM32L4 Series . . . . . . . . . . . . . . . . . . 49

Table 25. AES differences between STM32L1 Series and STM32L4 Series . . . . . . . . . . . . . . . . . . . 50

Table 26. USB differences between STM32L1 Series and STM32L4 Series. . . . . . . . . . . . . . . . . . . 51

Table 27. ADC differences between STM32L1 Series and STM32L4 Series. . . . . . . . . . . . . . . . . . . 52

Table 28. DAC differences between STM32L1 Series and STM32L4 Series. . . . . . . . . . . . . . . . . . . 54

Table 29. COMP differences between STM32L1 Series and STM32L4 Series . . . . . . . . . . . . . . . . . 55

Table 30. OPAMP differences between STM32L1 Series and STM32L4 Series . . . . . . . . . . . . . . . . 56

Table 31. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

DocID027094 Rev 3 5/58

AN4612 List of figures

List of figures

Figure 1. LQFP144 compatible board design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 2. LQFP100 compatible board design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 3. LQFP64 compatible board design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 4. LQFP48 compatible board design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 5. BGA132 compatible board design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 6. BGA100 compatible board design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 7. BGA64 compatible board design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 8. Generation of clock for SAI master mode (in case MCLK is needed). . . . . . . . . . . . . . . . . 48

STM32L4 Series overview AN4612

6/58 DocID027094 Rev 3

1 STM32L4 Series overview

The STM32L4 Series forms a perfect fit in terms of ultra-low-power, performances, memory

size, and peripherals at a cost effective price.

In particular, the STM32L4 Series allows higher frequency/performance operation than

STM32L1 Series, including a Cortex®-M4 @80 MHz versus Cortex®-M3 @32 MHz and

optimized Flash memory access through the adaptive real-time memory accelerator (ART

Accelerator™).

The STM32L4 Series products are divided in categories as per Table 1. This is done in

order to easily refer to each group of products in the rest of the document.

The STM32L4 Series includes a larger set of peripherals with advanced features and

optimized power consumption compared to the STM32L1:

•Touch sensing controller (TSC)

•Controller area network (bxCAN)

•Single wire protocol interface (SWPMI)

•Serial audio interface (SAI)

•Low-power UART (LPUART)

•Infrared interface (IRTIM)

•Low-power timer (LPTIM)

•Digital filter for sigma delta modulators (DFSDM)

•Voltage reference buffer (VREFBUF)

•Quad-SPI interface (QUADSPI)

•Firewall (FW)

•Additional SRAM2 (32 KB for Cat. 2 devices, 16 KB for Cat. 4 devices) with data

preservation in Standby mode

•Clock recovery system (CRS) for USB (for Cat. 4 devices)

The Cat. 4 devices implement a reduced set of features compared to the Cat. 2 devices:

•No FMC (external memory controller for static memory)

•SRAM1 limited to 48KB instead of 96KB on Cat. 2 devices

•No Digital filter for sigma delta modulators (DFSDM)

•USB FS instead of OTG FS

It also provides optimized power consumption and enriched set of low-power mode.

Table 1. Product category overview

Type Part number

Category 2(1)

1. Category 2 devices are referred as “Cat. 2” devices within this document.

STM32L476xx, STM32L486xx

Category 4(2)

2. Category 4 devices are referred as “Cat. 4” devices within this document.

STM32L433xx, STM32L443xx, STM32L432xx, STM32L442xx

DocID027094 Rev 3 7/58

AN4612 STM32L4 Series overview

This migration guide is only covering migration from STM32L1 to STM32L4 and as a

consequence new features present on STM32L4 Series but not already present on

STM32L1 are not covered in this document (please refer to the STM32L4 reference

manuals and datasheets for an exhaustive picture).

STM32L4 increases low-power efficiency in dynamic mode (μA/MHz) still reaching very low

level of static power consumption on various available low-power modes.

The detailed list of available features and packages for each product can be found in the

respective datasheet.

Hardware migration AN4612

8/58 DocID027094 Rev 3

2 Hardware migration

Only LQFP48, LQFP64, LQFP100, LQFP144, BGA64, BGA100, BGA132 are available on

both families. The other packages available on STM32L1 family are not available on

STM32L4 family.

The list of available packages in the STM32L4 Series is listed in below Table 2

The ultra-low-power STM32L4 and STM32L1 Series present a high level of pin

compatibility. Most peripherals share the same pins in the two series.

The transition from the STM32L1 Series to the STM32L4 Series for QFP and BGA

packages is easy since only a few pins are different (refer to Table 3 and Table 4).

For the WLCSP packages the transition is less easy because the pinout is different. This is

due to the fact that devices of STM32L1 Series and STM32L4 Series have different die

sizes.

asdf

Table 2. Packages available on STM32L4xx series

STM32L4xx

Size (mm x mm) Applicable lines

Cat. 2 Cat. 4

UFQFPN32 - x (5x5) STM32L432xx, STM32L442xx

LQFP48 - x (7x7) STM32L433xx, STM32L443xx

UFQFPN48 - x (7x7) STM32L433xx, STM32L443xx

WLCSP49 - x (3.141 x 3.127) STM32L433xx, STM32L443xx

WLCSP64 - x (3.141 x 3.127) STM32L433xx, STM32L443xx

LQFP64 x x (10x10) STM32L433xx, STM32L443xx

STM32L476xx, STM32L486xx

UFBGA64 - x (5x5) STM32L433xx, STM32L443xx

WLCSP72 x - (4.4084 x 3.7594) STM32L476xx, STM32L486xx

WLCSP81 x - (4.4084 x 3.7594) STM32L476xx

LQFP100 x x (14x14) STM32L433xx, STM32L443xx

STM32L476xx, STM32L486xx

UFBGA100 x x (7x7) STM32L433xx, STM32L443xx

UFBGA132 x - (7x7) STM32L476xx, STM32L486xx

LQFP144 x - (20x20) STM32L476xx, STM32L486xx

Table 3. STM32L1 Series and STM32L4 Series pinout differences (QFP)

STM32L1 Series STM32L4 Series

QFP

100

QFP

144 Pinout QFP

48(1)

QFP

100

QFP

144 Pinout

1 1 6 6 VLCD 1 1 6 6 VBAT

- - - 95 VDD - - - 95 VDDIO2(2)

DocID027094 Rev 3 9/58

AN4612 Hardware migration

- - - 131 VDD - - - 131 VDDIO2(2)

- - 73 106 PH2 - - 73 106 VDDUSB(2)

36 48 - - VDD 36 48 - - VDDUSB(2)

44 60 94 - BOOT0 44 60 94 - PH3-BOOT0(1)

1. Only for cat. 4 devices

2. VDDIO2 and VDDUSB pins can be connected externally to VDD.

Table 4. STM32L1 Series and STM32L4 Series pinout differences (BGA)

STM32L1 Series STM32L4 Series

BGA64 BGA100 BGA132 Pinout BGA64(1)

1. Only for cat. 4 devices

BGA100(1) BGA132 Pinout

B2 E2 E2 VLCD B2 E2 E2 VBAT

- - G7 VDD - - G7 VDDIO2(2)

2. VDDIO2 and VDDUSB pins can be connected externally to VDD.

- C11 C11 PH2 - C11 C11 VDDUSB(2)

--G3PF6- - G3 PG11

--G4PF7- - G4 PG6

--H4PF8- - H4 PG7

--J6PF9- - J6 PG8

- - K1 NC - - K1 PG15

G1 - - VREF+ G1 - - PC3

E5 - - VDD E5 - - VDDUSB(2)

H1 - - VDDA H1 - - VDDA / VREF+

B4 A4 - BOOT0 B4 A4 - PH3-BOOT0(1)

Table 3. STM32L1 Series and STM32L4 Series pinout differences (QFP) (continued)

STM32L1 Series STM32L4 Series

QFP

100

QFP

144 Pinout QFP

48(1)

QFP

100

QFP

144 Pinout

Hardware migration AN4612

10/58 DocID027094 Rev 3

Recommendations to migrate from STM32L1 Series board to a STM32L4

Series board

VLCD pin in STM32L4 Series is now multiplexed on PC3 GPIO (pin 29 on QFP144, pin 18

on QFP100, pin 11 on QFP64, pin K2 on BGA132/BGA100) through alternate function

programming in STM32L4 Series.

This implies that other functions in STM32L4 Series PC3 pins cannot be used on PC3 when

LCD is used by the application.

This also implies that the STM32L1 Series PC3 related alternate functions, if used by the

application, should be mapped onto other STM32L4 Series pins.

VBAT or VDD supply (if no specific VBAT power is used), should now be connected to:

•pin 6 (QFP144 and QFP100)

•pin 1 (QFP64/QFP48)

•pin E2 (BGA132/BGA100).

•pin B2 (BGA64)

GPIO PH2 is now used for dedicated VDDUSB power supply

•pin 106 (QFP144)

•pin 73 (QFP100)

•pin C11 (BGA132)

GPIO PH2 cannot be used as regular GPIO anymore (no PH2 GPIO in STM32L4 Series).

On BGA132, several GPIOs from STM32L1 Series are mapped on different GPIOs in

STM32L4 Series:

•PF6 (pin G3) mapped to PG11 on same pin

•PF7 (pin G4) mapped to PG6 on same pin

•PF8 (pin H4) mapped to PG7 on same pin

•PF9 (pin J6) mapped to PG8 on same pin

On BGA64, ball G1 used for VREF+ signal on STM32L1 Series is now used as GPIO PC3

(multiplexed with VLCD) on STM32L4 Series and the VREF+ signal is multiplexed with

VDDA on ball H1.

Also not connected (NC) pin K1 in STM32L1 Series can now be used as GPIO PG15 in

STM32L4 Series.

The boot pins are different in both families. The BOOT0 is multiplexed with PH3 GPIO on

STM32L4 family (Cat. 4 devices). Please refer to Section 3: Boot mode selection on

page 14 for details. Those changes do not impact the board design.

The figures below show examples of board designs migrating from STM32L1 Series to

STM32L4 Series.

Altri manuali per STM32L1 Series

Questo manuale è adatto per i seguenti modelli

Indice

Altri manuali ST Microcontrollore

ST UM2334 Manuale utente

ST STM32F4DISCOVERY Manuale utente

ST STM32F103 series Istruzioni per l'installazione e il funzionamento

ST STEVAL-ISB68WTX Manuale utente

ST STM32H74xI/G Manuale utente

ST STEVAL-BFA001V1B Manuale utente

ST STM32 Nucleo Manuale utente

ST 32F429IDISCOVERY Manuale utente

ST STM8A Istruzioni per l'installazione e il funzionamento

ST STM32 Series Istruzioni per l'installazione e il funzionamento

ST STM32F103 series Istruzioni per l'installazione e il funzionamento

ST ST25DV-I2C Manuale utente

ST UM2966 Manuale utente

ST STM32F100 Series Istruzioni per l'installazione e il funzionamento

ST STM32H723 Manuale utente

ST SPC574S-DISP Sphaero Discovery+ Manuale utente

ST STM32F4 Series Manuale utente

ST STM32F0DISCOVERY Manuale utente

ST STM32H7B3I-DK Manuale utente

ST STM32 Nucleo Manuale utente

ST STM32F072 Manuale utente

ST ST7260 Series Manuale utente

ST STM32G0 1 Series Manuale utente

ST UM2135 Manuale utente

Manuali Microcontrollore popolari di altre marche

AMS

AMS AS7261 Demo Kit Manuale utente

Novatek

Novatek NT6861 Manuale utente

Espressif Systems

Espressif Systems ESP8266 SDK Guida all'installazione

Nuvoton

Nuvoton ISD61S00 ChipCorder Guida

STMicrolectronics

STMicrolectronics ST7 Assembler Linker Manuale utente

Texas Instruments

Texas Instruments Chipcon CC2420DK Manuale utente

Lantronix

Lantronix Intrinsyc Open-Q 865XR SOM Manuale utente

NEC

NEC 78GK0S/K 1+ Series Istruzioni per l'installazione e il funzionamento

Mikroe

Mikroe SEMITECH N-PLC Click Istruzioni per l'installazione e il funzionamento

Intel

Intel Agilex Manuale utente

Cypress

Cypress CY4607 HX2VL Manuale utente

DIGITAL-LOGIC

DIGITAL-LOGIC MICROSPACE Manuale utente

Texas Instruments

Texas Instruments TMS320F2837 D Series Manuale utente

CYPRES

CYPRES CY14NVSRAMKIT-001 Manuale utente

Texas Instruments

Texas Instruments INA-DUAL-2AMP-EVM Manuale utente

Espressif Systems

Espressif Systems ESP8266EX Istruzioni operative

Abov

Abov AC33M8128L Manuale utente

Laird

Laird BL654PA Manuale utente