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Yugenthar
Associate III
April 28, 2023
Question

How to use the SDRAM in stm32f7 series

  • April 28, 2023
  • 7 replies
  • 5857 views

Hello everyone ,

I am Yugenthar

Right now i am working in embedded development platform . So i have one doubt guys.I have using stm32f746-disco board.

I am displaying one image in LCD screen (800x760)so pixel size is incresing.

my code is runing in flash memory

my compiler is show one error "your flash is overflow"

then I have decided move to SDRAM and store my code

But I have not perfect in SDRAM so any one give the sollution any material or tutorial link


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7 replies

LCE
Principal II
April 28, 2023

EDIT: sorry, you want to know how to use the external RAM on the disco board...

What about starting with calculating how many bytes you need, and then compare to the controller's spec?

If your data is too big, you might need external RAM or flash.

From your screenshot: definitely you need some external memory...

Isn't there anything on that discovery board?

Yugenthar
YugentharAuthor
Associate III
April 28, 2023

BRO i need one doubt .

how to Calculate byte and how to add the external ram.

so i am not clear in microcontroller byte calculation

then one doubt how to find the internal sdram in controller then how to store the my code in sdram give the solution and any reference material or tutorial link

LCE
Principal II
April 28, 2023

Please remove the "select as best" from my 1st reply, because I'm not ansering your question at all.

Dude, basics, back to school!

8 bits = 1 byte, then something like uint32_t = 4 bytes, so an array of uint32_t u32example[500] has a size of 500 x 4 = 2000 bytes.

Memory sizes are usually given in bytes.

... and maybe I'm a SIS? ;)

Yugenthar
YugentharAuthor
Associate III
April 28, 2023

Thank for your Help LCE (SIS)

I really enjoy your byte calculation concept and tech.

Then I calculate my code array byte is to long

I have refer in stm32 programing manual is give flash memory concept .but my doubt how to find the Full flash memory in microcontroller So I am not fit in memory concept

Before i write the code basic level my compiler is working good.

Now I'm moving image processing high level code not work so my senior is suggest understand memory concept and utilize the memory

If I need your help in memory concept.

How to read the datasheet in memory concept

LCE
Principal II
April 28, 2023

> Thank for your Help LCE (SIS)

Not really, I was just making fun of your "BRO", which we usually don't use here.

This is a technical and rather humorless forum!

Yugenthar
YugentharAuthor
Associate III
April 28, 2023

Okay sister

.

your Good name .

Tesla DeLorean
Guru
April 29, 2023

When running out of Internal Flash the External QSPI Flash would be where to park large graphic resources. Would need to select an External Loader to download data to it, and then App side code to bring up the pins and memory interface.​

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Yugenthar
YugentharAuthor
Associate III
May 5, 2023

Okay bro...

Thank you for you information.

first of all I don't know the QSPI concept. I have study the QSPI Concept because one doubt So QSPI is internal memory or external memory.......

Tesla DeLorean
Guru
May 5, 2023

It is a low-pin-count external memory. Often an 8-pin device, with 6 pins on the STM32 side for communication.

The STM32F746G-DISCO has a 128-Mbit (16MB) Quad-SPI Flash memory.

I don't recall if it's a Micron or Macronix device, but it should be supported via the BSP code available for the board.

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OWLchan
Associate III
May 5, 2023

BRO.....the error showing on your project is not SDRAM, this I don't know how to use but if it is "FLASH" error... this person will help you "(1) QSPI in STM32 || Boot from EXT Memory || XIP || N25Q - YouTube " by the way please watch the video carefully because I made a mistake in the loader part at first.

or you can use touch gfx, it will create functions like SDRAM, QSPI for you :beaming_face_with_smiling_eyes: :beaming_face_with_smiling_eyes: :beaming_face_with_smiling_eyes:

Yugenthar
YugentharAuthor
Associate III
May 6, 2023

Bro I know this is not SDRAM error actual this indication is "flash overflow" so I will move the SDRAM concept.

My Doubt:

Actual STM32 is available on internal SDRAM

Yugenthar
YugentharAuthor
Associate III
May 6, 2023

okay brother."thank you"

I will watch this video then any doubt I have ask to you

Bro Actual right now working Show the image to LCD display..size is 800x700 Using lcd image convertor application image is convert to to c file I thing array size is so big .

OWLchan
Associate III
May 9, 2023

do you want to use sdram to put that image on screen, or use external flash to save it??

i just found a nice example, that can use both external flash and sdram, but it is stm32f7508 dk same as my board, hope it helps you 

put the image here and try to compile it 

Mula-Gabriel/STM32F7508-DK-LVGL-AzureRtos-Template (github.com)


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