Maxim Integrated 73S12xxF USB-CCID Host GUI - Manual (Page 14)

73S12xxF USB-CCID Host GUI Users Guide UG_12xxF_037
14 Rev. 1.1
2.1.8 DFU Frame
The DFU frame is divided into two sub-frames. The Detach sub-frame is used to initiate a DFU process.
The DFU Requests sub-frame consists of five DFU command buttons that can be used to test DFU
requests individually. Additionally, the DFU frame displays the version numbers of the boot loader and
firmware application that are currently running in the smart card reader.
When a smart card reader is selected, the Detach sub-frame is enabled, but the DFU Requests
sub-frame remains disabled until the smart card reader enters DFU mode.
Figure 10: DFU Frame
2.1.8.1 Detach Sub-frame
A smart card reader normally operates in CCID mode. To initiate a firmware upgrade, the host
application must detach the smart card reader so that the reader will reset and boot up again as a DFU
device. The host application performs this detachment by sending either a DFU Detach (DFU_DETACH)
or CCID Escape command to the reader. Select either the DFU Request or Escape Command button,
and then click the Detach button. The smart card reader resets and disappears from the Card Reader
list. It then reboots in DFU mode. The host application automatically detects this DFU device and
displays its name in the Card Reader list box.
At this point, the host application disables the Detach sub-frame. Selecting the DFU device activates the
DFU Requests sub-frame.