Peripheral migration

TN1176

6/15

DocID026267 Rev 1

3

Peripheral migration

Table 4 and Table 5 list the main product peripherals and system features for both product

pairs. The common peripherals are supported with the dedicated firmware library without

any modification. The users can change the instance and all the related features (clock

configuration, pin configuration, interrupt/DMA request).

Peripherals such as Touch sensing, Backup registers are different in the STM32L15xx6/8/B

device and must be updated by software to benefit from the latest enhancements and

correct functionality of STM32L15xx6/8/B-A device.

The extended peripherals such as: RTC, LCD rail decoupling, PCROP (Proprietary code

read out protection), clock (CSS on LSE) are fully backward compatible with no need to

firmware update.

The main peripherals changes are described in Section 3.1: Main peripheral/system

changes. The changes which are also needed in the development tools configuration are

described in Section 4: Development tool adaptations.

Table 4 presents the differences between STM32L15xx6/8/B and STM32L15xx6/8/B-A

devices regarding the peripherals and system differences, as well as the impact to needed

software changes. The differences are highlighted in gray.

Function

STM32L15xx6/8/B

STM32L15xx6/8/B-A

Behavior / impact to software

Core @ 32MHz

Max DMIPS/MHz

1.25

1.25

Flash [KB]

up to 128

up to 128

RAM [KB]

up to 16

up to 32

Enhancement. the application can

use larger RAM memory space.

EEPROM [KB]

44

Backup registers

[B]

80

20

Software can store only up to

20 bytes into backup registers. See

STM32L15xx6/8/B-A errata sheet for

details.

Flash interface

[bits]

64/32

64/32

Bootloader

USART1/2

USART1/2

DMA / channels

1 / 7ch

1 / 7ch

USART

33

SPI / I2S

2 / 0

2 / 0

I2C

22

USB 2.0

1 x FS

1 x FS

LCD [seg x com]

8 x 40

8 x 40