huangandi
huangandi
Thank you for your reply
I am using USB_CDC_ACM_HOST , Using USB full speed interface, i am trying to plug USB_CDC_ACM_DEVICE and it is USB full speed interface too
> Hi [@andy817501](https://github.com/andy817501) which plateforme/target are you using ? Stm32 ? I am using vscode + gcc + stm32
But I use USB_OTG_FS dma enable=ENABLE and turn on dcache to make it work as a cdc device, It can work normally,I don't need to turn off dcache or use...
@ALABSTM I discovered after porting that USB_cdc_host DMA and Dcache are working together to produce anomalies,but the usb_cdc_device is no such issue
yes，i had a look at the [x-cube-azrtos-h7](https://github.com/STMicroelectronics/x-cube-azrtos-h7) repository , and make sure The DTCM (0x20000000) memory region do not be used ,and make sure to configure the USB pool memory...
for Ux_Device_CDC_ACM , I Can use the dache + dma work together , But for Ux_Host_CDC_ACM i can not ,I have already provided detailed information before
I had look this issue, but it only Mentioning the closure of dache，and use not cacheable Memory ，for the closure of dache i think it is unacceptable , for not...
HI! @ALABSTM Tell me if you need any help or further information.
yes, I Configure the MPU attributes as Normal Non Cacheable for RAM_D2,and use RAM_D2 as the usb_cdc_device's dma buffers is permissible,but I can not use the usb_cdc_host with dma