STM32U5G9 USB device ux_device_stack_initialize() error 18

Kelly3 · ‎2025-07-24

I am using STM32U5G9 implementing USB MSC device. When calling function ux_device_stack_initialize(), it returns error 18, which is correspond to UX_MEMORY_INSUFFICIENT. This error happens line 397 of use core file ux_device_stack_initialize.c.

if (endpoints_pool -> ux_slave_endpoint_transfer_request.ux_slave_transfer_request_data_pointer == UX_NULL)

{

status = UX_MEMORY_INSUFFICIENT;

break;

}

May I know how to fix this error?

FBL · ‎2025-10-23

Hi @Kelly3

The USBX device stack relies on a memory pool for dynamic allocations. If this pool is too small or not properly initialized, allocations will fail. Try to increase the size of the memory pool buffer passed to USBX.

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