When I plug in 64 and 128 gb usb, it says the library is constantly connected and disconnceted. But 16gb usb works clearly.

[cvarl.1]

Hello,

I use USB MSC modules codes which provided by ST ( HAL Library USB )

Actually I can use correctly my application with 16GB ,8GB ,4GB USB.

But When I plug in 64GB USB or 128GB, it is not working.

it is periodically transmit "USB Device disconnected" and "USB Device Connected" like in attacment.

What could be the cause of this problem ?

[Tesla DeLorean]

Not something that I've dug into, but all the source is available.

These capacities tend to need EXFAT so there might be a check for a specific capacity, or support for the file system present on the card.​

Would suggest analyzing code paths​ pertaining to SCSI GET CAPACITY command queries.