Hello, I'am using the AT91SAM9RL64 Eval Board. To get to know USB, I extended the USB-Example "usb-device-core-project-1.4-at91sam9rl-ek" from the ATMEL homepage. I extended the configuration descriptor with two endpoint descriptors, one bulk in- EP (1) and one bulk out EP (6). The size of the endpoints is 512 byte. DMA is activated. For testing I call the USBD_Write- function with the following parameters: USBD_Write( 0x1,&data,512,(TransferCallback)usbdWriteCallback,0); Directly after this, my Callback- function is executed, because an interrupt is triggered by the DMA Channel1, but I didn't read Data by the host. In my opinion this interrupt should only be triggert, when the host read's data. Do you know a possible reason for this behavior? What I have to consider? On the host I use the LibUsb-Win32 driver/library. Thx Torsten
Maybe you can compare your code with the cdc-serial project also in the software-package. It also sets up bulk-endpoints and descriptors are included. It might be easier to adapt this example to your needs than to add code to the core-example.
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