AnsweredAssumed Answered

How to disable use of external DRAM Module on the STM32746G Discovery Board?

Question asked by Andrew Hazelton on Oct 8, 2017
Latest reply on Oct 24, 2017 by Andrew Hazelton

Hi All.


I am currently building a project based on the “STemWin Demonstration” example in the below directory, on the STM32746G Discovery Board. All of the examples use the external DRAM Module (MT48LC4M32B2B5-6A  by MICRON). This IC is now obsolete and I would prefer not to use it. Can someone please help me with the below 2 queries?


1)  Is the setup such that the use of the external DRAM Module automatic? As in, if you declare an  Array (i.e. int  Array[300] ) will the FMC automatically use the external DRAM if it needs to? Or can you only read/write to the external DRAM Module using functions HAL_SDRAM_Read() / HAL_SDRAM_Write()?


2)  How do I turn off the use of the external DRAM Module as I don’t wish to use this later on my custom PCB? The problem that I am finding is that if you simply comment out the "BSP_SDRAM_Init();" LCD screen fails to load and a black clear is displayed.  This is strange as I cannot find any of the following functions used in the project: BSP_SDRAM_ReadData, BSP_SDRAM_ReadData_DMA, BSP_SDRAM_WriteData, BSP_SDRAM_WriteData_DMA, HAL_SDRAM_Write, etc. I cannot see how the STemWin stack interfaces with the external DRAM Module.


Compiler:            IAR Workbench v8.11.3

Graphics:            STemWin

Hardware:           STM32746G Discovery Board

Demo Project:   C:\...\STM32Cube_FW_F7_V1.8.0\Projects\STM32746G-Discovery\Demonstration\STemWin\EWARM