STemWIN + SDRAM + LTDC

[Amez-Droz.Philippe]

Posted on June 20, 2016 at 19:57

Hello,

I use a STM32F429 Discovery board with an other Display (Newheaven 800x480,7 inches

http://www.newhavendisplay.com/nhd70800480efatxvctp-p-6912.html

I use the LTDC controller of the STM32F4 to control the display. The buffer for the display is in the SDRAM and I use multibuffering to avoid flickering.

The display is OK, I seen the widget on it but the processor is very slow. Approvimatively 1 seconds to refresh a picture and copy the content from one buffer to the other.

I suppose it's come from the access conflict to the SDRAM but I don't how to configure it.

Here is my clock configuration:

My FMC config is here:

Do you knoe how to configure it?

Thank in advance.

Best regards.

#ltdc #stemwin #sdram

[Walid FTITI_O]

Posted on June 21, 2016 at 16:14

Hi Bobino,

I recommend that you follow these both threads which can help you :

https://my.st.com/public/STe2ecommunities/mcu/Lists/STM32Java/Flat.aspx?RootFolder=https://my.st.com/public/STe2ecommunities/mcu/Lists/STM32Java/stm32cubemx%20init%20SDRAM%20in%20STM32F429NI&FolderCTID=0x01200200770978C69A1141439FE559EB459D758000F9A0E3A95BA69146A17C2E80209ADC21&currentviews=61

https://my.st.com/public/STe2ecommunities/mcu/Lists/STM32Java/Flat.aspx?RootFolder=https://my.st.com/public/STe2ecommunities/mcu/Lists/STM32Java/STM32CubeMX%20V1.1.0%20%2b%20SDRAM&FolderCTID=0x01200200770978C69A1141439FE559EB459D758000F9A0E3A95BA69146A17C2E80209ADC21&currentviews=521

Otherwise, I recommend you totake a look to the ''FMC_SDRAM'' example in the STM32CubeF4 and compare it to your code. Example is under this path: STM32Cube_FW_F4_V1.0\Projects\STM324x9I_EVAL\Examples\FMC\FMC_SDRAM

-Hannibal-

[Amez-Droz.Philippe]

Posted on June 21, 2016 at 21:31

Thank you Hannibal,

My SDRAM seems to be correctly connected.

I have mesured with an oscilloscope and the GUI_MULTIBUF_BeginEx takes 400mS to execute (Display 480x800 in 16 bits for the 3 colors and processor at 180MHz).

Don't know why.

Best regards and thanks

[Walid FTITI_O]

Posted on August 26, 2016 at 19:12

Hi Bobino, 

 I find some threads related to the same function issue, where SEGGER gives some suggestions. Check there and come back to tell me if that solve your issue or if you have further feedbacks. Follow : 

http://forum.segger.com/index.php?page=Thread&threadID=3297

, 

http://forum.segger.com/index.php?page=Thread&threadID=3390

, 

http://forum.segger.com/index.php?page=Thread&threadID=2756

-Hannibal-.