STM32 L452 : Programming using SWD interface

Shubham Jaiswal · ‎2017-09-28

Posted on September 29, 2017 at 07:03

Hello everyone,

I am working with STM32 L452 microcontroller. I'm trying to program this using SWD interface on ST link debugger of the Nucleo board. I am powering the L452 MCU via two different methods :

1) Using the 3.3V supply from the nucleo board

2) Using my custom power supply ( 30V---[buck conversion]---> 5V ---[LDO]----> 3.3V )

But in first case the programming results in success whereas it fails in the second case.

What is causing the problem here ?

PS : I'm using the following three pins from the SWD interface :

i) SWDIO

ii) SWCLK

iii) Gnd

#stm32l452 #swd-interface

AvaTar · ‎2017-09-29

Posted on September 29, 2017 at 11:29

Have you checked the stability of your 3.3V supply, especially during Flashing ?

Proper buffer caps on Vdd/Vdda ?

I am no hardware designer/expert, but it would be helpful to describe the hardware you use. ST eval board or custom design ?

Flash programming requires a higher current draw, possibly a problem on a low-power optimized design.