SDRAM 32bit bus can't be selected for STM32H7

[BHan.1]

Hello,

I'm trying to connect SDRAM to STM32 for the first time and I'm having trouble understanding the specs.

In the datasheet, it seems the FMC peripheral can support 32bit memory.

But when I use the Cube MX setting, I'm only able to select 16 bits for the Data.

Is there something that I'm missing in the data sheet?

[Tilen MAJERLE · Accepted solution]

If CubeMX does not allow you to select 32-bit data width, it normally means that package size doesn't support it. Which exact MCU part number did you take?

[BHan.1]

The MCU I'm using is STM32H743ZI and the FMC info pic is from the datasheet.

From your comment, I'm getting a feeling that the LQFP144 package doesn't support 32bit. I will look into it more.

[Tilen MAJERLE]

You are right, LQFP144 does not support 32-bit data bus.

[BHan.1]

I have a followup question. So now I'm looking for a SDRAM with 16bit data bus and 4 banks. It seems most of the RAMS with 128Mb is compatible with STM32 MCUs, but if the size is > 128Mb, then all the memories(Micron, ISSI) have an additional Differential CK# pin that needs to be synced with CK pin. I couldn't correlate the additional CK# pins with memory size, speed, DDR vs DDR2, but it's there. Does STM32H support differential clocks for SDRAM?