EEPROMs vs SD Cards. The Espruino Board has a built-in micro-SD card, and (micro-) SD card readers are readily available and can be connected to other boards running Espruino, communicating over SPI. Compared to EEPROM, an SD card: Has much higher capacity - the smallest SD cards are larger than the largest EEPROMs. SPI mode requires four pins (we'll discuss them in detail later) so it's not pin-heavy like some parallel-interface components. SD cards come in two popular flavors - microSD and SD. The interface, code, structure, etc is all the same. The only differences is the size. MicroSD are much much smaller in physical size. Third, SD cards are 'raw It will be connected to qspi controller like single spi flash memory. That won't work. The QSPI controller is not a general-purpose SPI peripheral; it can only be used for devices which conform to a particular serial flash protocol. SD cards are not such a device. If your image data does not fit into main memory, consider adding SDRAM to your 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 You can switch between SD mode and SPI mode of communication during power-up. By default, the card always starts in SD mode. The Arduino has to perform the switch using the Chip select and control lines. Once you put the SD card into SPI mode, you cannot change the communication mode without providing a power reset. Unlike previous adapters, it is not fixed for SPI usage, and can be used with SDIO hardware support. SDIO is a multi-pin data protocol (up to 4 data pins at once!) SDIO also tends to be able to be clocked faster than SPI. Of course, your speeds will vary depending on what microcontroller you hook it up to. When we used SDIO instead of SPI on Sc0I.

spi flash vs sd card