Question: How to know when the host has written some data to the device?
Answer: When data is sent out by the host and the device has the interrupts enabled, the INT# pin will be asserted and the FLAGS (bit 5) in the IRQ register will be set. Alternatively, the FLAGSx pins can be programmed so that the hardware interface can monitor the filling of the Out FIFO's. Please refer to the attached SX2 datasheet for more information
Note: The SX2 is not recommended for new designs
