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M30245 Group
Control Read Transfer
In setup stage, host notifies the device that it is control read transfer. Then, in data stage, data are
transmitted from the device to host through repetition of IN transaction. Finally, in status stage, OUT
transaction is executed (that the host transmits an empty packet of data length (0) to the device) to
complete the control read transfer.
Control Write Transfer
In setup stage, host notifies the device that it is control write transfer. Then, in data stage, data are
transmitted from the host to device through repetition of OUT transaction. Finally, in status stage, IN
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transaction is executed (that the device transmits an empty packet of data length (0) to the host) to
complete the control write transfer.
No Control Data Transfer
In setup stage, host notifies the device that it is no control data transfer. Then, in status stage, IN
transaction is executed (that the device transmits an empty packet of data length (0) to the host) to
complete the no control data transfer.
The execution result of setup stage and data stage are notified to host CPU in status stage. For
details of response format of control transfers, refer to USB2.0 specification.
Device Request
Concerning setup transaction in the setup stage of control transfer, format of its data phase has been
defined, which is called device request.
For standard (0) type, it is called standard device request, which is the basic device request to be
supported by all the USB devices.
For class (1) type, it is called class request. The USB implementers forum (USB IF) defines a device
class, and determines the configuration required in the class and the class request.
For each data format of the device request, refer to USB2.0 specification or the specification for each
class.
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
page 132 of 354
2. USB function
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