3.4.8.1 SDMMC0 Connector

The board features a 4-bit small-size microSD card connector (J42) connected to the SDMMC0 interface. The SDMMC0 communication is based on an 8-pin interface (clock, command, four data and power lines). The connector includes a card detection switch.

The SDMMC0 connector enables the system to boot from an SD card, provided that the correct binary file is copied to the root level of the card.

The SDMMC reset is triggered by the system reset signal, which cycles the SD card power using the MIC94085YFT high-side load switch. For more information about the MIC94085YFT device, refer to the product web page.

Figure 3-32. SDMMC0 Connector
Table 3-13. SDMMC0 Connector Signal Description
PIOSignal NameSignal Description
PA23SDMMC0_0.SDMMC_CDSD card detection
PA2SDMMC0_0.SDMMC_CLKSDIO clock
PA1SDMMC0_0.SDMMC_CMDSDIO command
PA0SDMMC0_0.SDMMC_DATA0SDIO data bit 0
PA3SDMMC0_0.SDMMC_DATA1SDIO data bit 1
PA4SDMMC0_0.SDMMC_DATA2SDIO data bit 2
PA5SDMMC0_0.SDMMC_DATA3SDIO data bit 3