The microcontroller used on the Preon32 radio module has a large number of interfaces. These interfaces can be used to control different peripherals with different protocols. In this example for the PreonVM, a serial flash memory module is controlled via SPI (serial protocol interface). In this example, the MX25L8005 flash used is operated with a frequency of 25 MHz. The corresponding chip select line is set for activation. In the example, the flash is completely erased in the first step. Two types of access are shown below. On the one hand this is the direct writing and reading from a fixed address. In the second variant, access is realized via so-called streams.