Summary of changes

We would like to introduce the new STM32L5 family:

• Cortex-M33 at 110 MHz
• Ultra-low-power MCUs
• software secure isolations with TrustZone

https://www.st.com/en/microcontrollers-microprocessors/stm32l5-series.html

Cube FW files are now available:
https://github.com/STMicroelectronics/STM32CubeL5

MBED-OS port has been implemented for NUCLEO-L552ZE-Q target:

• 512 Kbytes of Flash memory
• 256 Kbytes of SRAM
• Arduino support
• Trust Zone not enabled (out of box default configuration)

https://www.st.com/en/microcontrollers-microprocessors/stm32l552ze.html
https://www.st.com/en/evaluation-tools/nucleo-l552ze-q.html

This is step 1 of STM32L5 work!
Next steps:

• DISCO-L562QE target introduction
• Trust Zone enablement
• TFM and PSA support

Note that STM32L5 MCUs are not available yet in tools/arm_pack_manager/index.json

Impact of changes

Migration actions required

Documentation

Pull request type

[x] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

Test results

[] No Tests required for this change (E.g docs only update)
[x] Covered by existing mbed-os tests (Greentea or Unittest)
[] Tests / results supplied as part of this PR

Reviewers

@MarceloSalazar
@ARMmbed/team-st-mcd
@PLFSTM
@jamike