This article demonstrates how to use the Secure Digital (SD) media format to expand the MAXQ2000’s nonvolatile data storage. The low-power, low-noise MAXQ2000 microcontroller is suitable for a variety of applications. It stores nonvolatile data in flash memory and has 32kWords (64kB) flash capacity that is shared with user code space. But what if your application requires more nonvolatile storage? This article demonstrates how to use the Secure Digital (SD) media format to expand the MAXQ2000’s nonvolatile data storage.