STM32F7: Ram needed for a 800x480 24bit display.

[MDell.1]

Dear All,

I'm approaching for the first time STM32F7 family. My need is to use this microcontroller essentially to drive an 800x480 TFT LCD 24 bit. It's the first time that I'm doing it.

Reading online the RAM needed for a similar resolution is 800*480*24/8= almost 4MB.

Why on the ST evaluation boards there are alway 128MB of RAM? Is there a reason why this bigger RAM is necessary? Consider that I just need to drive this LCD and maybe use other peripherals like USB HOST and ETHERNET.

Furthermore, I see that the RAM indicated in the evaluation boards are very expensive on e-commerce sites like digikey (more than 8€ for 100 pcs.) while I've found other RAM ICs that are really cheaper. For example the memory IS42S16400J-7TL costs 1,2€ for 100 pcs. Do you think I could use this kind of ram instead of the one indicated in the datasheet?

Thank you in advance and sorry if my question maybe are elementary but as I said before it's the first time that I'm approaching it.

Mattia

[berendi]

We are using IS42S16400J-7TL with STM32F429ZI and STM32H743II MCUs, it is used on the 32F429IDISCOVERY boards by ST as well. I can see no reason why it would not work with STM32F7.

I could not get it working at 133 MHz CAS 2, but works fine at 143 MHz CAS 3. The display was stable in 800x480x32 bit mode even at 100 MHz which is I think the most what the STM32F7 can do.

[MDell.1]

Thank you very much for your answer!!

[Slske.1]

I've taken a note to upgrade my respectable knowlege of C to at the least 'Good'. I'm searching for documentation of the architecture of my particular chip to advantage on this page to put a higher know-how of what i'm in reality interacting with, but dont recognize precisely in which to appearance.