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STM32 resetting on first sdram access

Question asked by Fabrizio Pizzolato on Aug 29, 2017
Latest reply on Aug 30, 2017 by Fabrizio Pizzolato

Good morning, I have a STM32F429 based board, the MCU is interfacing a Micron SDRAM (MT48LC4M32B2). We successfully configured the sdram interface using the FMC driver. We use 1.4.3 version.

We had a first production round where about half of the boards have the following problem: on the very first access to the sdram the MCU hard resets. I could verify that a 1ms negative pulse is present on the MCU reset line. After this reset the application restarts and access to the SDRAM is executed with no problems. 

Note: by saying first access I mean the first time the memory is used. I always configure it (by using low level functions from the driver) without problems. At a later time (actually through an external command) I create a pointer to the first memory location in sdram and try to use it, and this is when the problem occurs.

Anybody here had similar problems? Any ideas on how to identify the problem?

 

thank you very much

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