Once the kernel module is loaded, the system will create a device file, typically or /dev/ttyACM0 .
Many versions of this driver are not digitally signed by Microsoft. Modern Windows versions (7, 8, 10, and 11) will block them by default. Go to > Update & Security > Recovery . Under Advanced startup , click Restart now .
Download the latest "Spreadtrum Driver Installer."
The (SCI = Serial Communication Interface) is not a standard UART-to-USB bridge like FTDI or CP2102. Instead, it is a proprietary diagnostic and engineering interface embedded within Spreadtrum/Unisoc mobile phone chipsets (SC77xx, SC98xx, UIS78xx, Tiger series). It appears as a USB CDC-ACM or vendor-class device, but implements a packetized protocol over bulk endpoints to access multiple logical channels (modem log, application log, GPS, secure debug, calibration). spreadtrum sci usb2serial ok
If your device is listed with a yellow triangle or as an "Unknown Device," you need to install the drivers manually to reach the "OK" status. 1. Pre-Installation: Disable Driver Signature Enforcement
If the installation fails, uninstall the current driver via Control Panel, restart your PC, and install the driver again as administrator. Conclusion
Press or F7 to select "Disable driver signature enforcement." 2. Download and Extract the Driver Once the kernel module is loaded, the system
Hold down the key while clicking Restart in the Windows Start Menu.
Interface 0 (CDC Control) bInterfaceClass 0x02 (CDC) bInterfaceSubClass 0x02 (ACM)
Click .
If your device manager displays "Spreadtrum SCI USB2Serial OK" with a yellow exclamation mark—or if your flashing software (like SPD Upgrade Tool or Miracle Box) fails to detect the COM port—one of three issues is typically at play:
Navigate to: > Advanced options > Startup Settings > Restart .
Ultimate Guide to Spreadtrum SCI USB2Serial: How to Achieve the "OK" Status Go to > Update & Security > Recovery