Peripheral Migration; Stm32 Product Cross-Compatibility; Table 8. Peripheral Compatibility Analysis Stm32L1 Series Versus Stm32L4 Series - ST STM32L1 Series Application Note

AN4612
4

Peripheral migration

4.1

STM32 product cross-compatibility

The STM32 series embeds a set of peripherals which can be classified in three categories:
•
The first category is for the peripherals that are common to all products. Those
peripherals are identical on all products, so they have the same structure, registers and
control bits. There is no need to perform any firmware change to keep the same
functionality at the application level after migration. All the features and behavior
remain the same.
•
The second category is for the peripherals that present minor differences from one
product to another (usually differences due to the support of new features). Migrating
from one product to another is very easy and does not require any significant new
development effort.
•
The third category is for peripherals which have been considerably modified from one
product to another (new architecture, new features...). For this category of peripherals,
migration will require new development at application level.
Table 8 gives a general overview of this classification.
The "software compatibility" mentioned in the table below only refers to the register
description for "low level" drivers.
The STMCube™ hardware abstraction layer (HAL) between STM32L1 and STM32L4
Series is compatible.

Table 8. Peripheral compatibility analysis STM32L1 Series versus STM32L4 Series

Nb
Nb
inst.
Peripheral inst.
Cat.
in L1
2/4
SPI 3
I2S 2
WWDG 1
IWDG 1
DBGMCU 1
CRC 1
EXTI 1
USB FS 1 0/1
USB OTG
0 1/0
FS
(migrating from STM32L1 Series to STM32L4 Series)
Software
3
Partial compatibility
0
1 Full Compatibility
1 Full Compatibility
1 Full Compatibility
1 Partial compatibility
1 Partial compatibility
Partial compatibility
No compatibility
DocID027094 Rev 3
Compatibility
Pinout
I2S is no more supported by SPI but
replaced by dedicated Serial Audio
Interface (SAI) in STM32L4 Series.
Partial compatibility
Some alternate function not mapped on
same GPIO for SPI1.
NA
NA
NA
NA Additional features in STM32L4 Series.
Only PH2 GPIO not available as EXTI
Full compatibility
input in STM32L4 Series.
Additional features on STM32L4 Cat. 4
Full compatibility
devices.
New peripheral (OTG FS) on STM32L4
Full compatibility
Cat. 2 devices.
Peripheral migration
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