This breakout is for a fascinating chip - it looks like an SPI Flash storage chip (like the GD25Q16) but its really an SD card, in an SMT chip format. You can wire up like an SD card breakout and use the SD card libraries you already have for your microcontroller. For example, you can use the built in SD library in Arduino, or for CircuitPython we have an sdcard library. The breakout will act Figure 1. SD Transfer Mode 2.2 SPI Transfer Mode Operation The SPI compatible communication mode of the SD Me mory Card is designed to communicate with a SPI channel, commonly found in various microcontrollers in the market. The interface is selected during the first reset command after power-up and cannot be changed as long as the part is Standard voltages are used for industrial grade SD cards. Bus Information. SD cards operate with a default bus protocol of SD mode. However, if a simpler or slower bus is needed, the card can be configured for SPI mode. While in SPI mode, SD cards operate in one-bit bus widths. In SD mode, the cards use a serial clock mode for bus widths of Serial and Parallel Flash Memory. Flash Memory with Embedded MAC Addresses; SuperFlash® Memory Technology; Getting Started with SuperFlash® Technology; Serial SRAM and Serial NVSRAM. Parallel EEPROM. OTP EPROM. Smart Memory Controllers Flash is always be ROM :) Now SD-card if "loved baby" for Altera and Rockedboards, there full works all worked applications: Linux and RTOSes. From QSPI not boot nothing, at least, in capable examples! Although, may be symmetrycal :) HPS for embedded application must boot from any flash, which may be soldered on board and visible in address I'm trying to work with the micro sd card module and stm32 with spi. I have formatted my micro sd card but the received output (using f_getfree function and Uart), claims that my free space is 0. which cannot be true as I have tried 2 different m-sd cards with different sizes but same results. /* USER CODE BEGIN Includes */ #include "fatfs_sd.h Most SD cards are sold pre-formatted with a FAT file system on top of an MBR partition scheme. The Serial Peripheral Interface (SPI) Bus is an access mode that implements a simpler subset of the SD protocol for use with a standard SPI interface. This mode is widespread due to its extensive use in embedded systems, especially resource-critical Unlike NAND flash, NOR flash is random-access memory, allowing direct access to any location without block-level addressing, making it suitable for frequent reading and writing of data. NOR flash memory also allows for byte-level writing, improving its write endurance compared to NAND flash memory. The memory cells are organized in a grid and f3Zu.