[STM32H750]I chose sdram as my running ram, but it takes a long time to initialize

[Passerby]

Hello:

I have external sdram on FMC bus. I initialized with bootloader, mapped sdram to Bank2(0xD000 0000), and jumped to APP to run. The configuration of my APP is shown in the figure.

I find that the more ram is used in the APP, the longer it takes for bootloader to jump to the app.The speed is about 1.1MB/s.

However, when I ran the read and write tests in bootloader（sdram）, it took about a few hundred milliseconds to write all of them,Why is this?

[Passerby · Accepted solution]

Hello,

I solved the problem. The reason is that when external Qspi-Flash performs xip operation, the mpu is disable before jumping, so it should not be disable, otherwise there will be some problems.

Thanks!