The O2Micro Integrated MMC/SD Controller is a hardware component commonly found in laptops and mobile devices. It provides support for MMC (MultiMediaCard) and SD (Secure Digital) cards, allowing the system to read from and write to these types of memory cards, which are commonly used in cameras, phones, and other portable devices.
The O2Micro Integrated MMC/SD Controller typically requires specific driver software to work properly in a Windows environment. If the driver is not installed or is malfunctioning, your computer may fail to recognize or access MMC/SD cards when they are inserted into the card reader.