1.usb worked at host mode.
2.usb protocol is BULK.
3.usb worked in DMA mode.
when Bulk out op completed, I do recv the complete queue msg. and in ISR I set a loop wait USB0_HOST_TXCSR(bit1) is clearing.
the communication is all right.
but very SLOWLY.
I traced the code. Find such code:
"while(USB0_HOST_TXCSR&(1<<0) {... }"
It takes 99.9%'s running time.
