SPRADO8 March 2025 AM62L
Processor MMC1 (CMD, CLK and Data) interface IOs are powered by VDDSHV3 supply rail (IO supply for MMC1 IO group) and MMC2 (CMD, CLK and Data) interface IOs are powered by VDDSHV4 supply rail (IO supply for MMC2 IO group).
VDDSHV3 and VDDSHV4 are designed to support power-up, power-down, or dynamic voltage switching independently of other power rails, allowing the operating voltage to change from 3.3V to 1.8V as the transfer speed increases.
VDDSHV3 and VDDSHV4 supplies are required to start with 3.3V and allow changing to 1.8V when software is ready to change the IO supply voltage.
For generating the dynamically changing 3.3V or 1.8V supply, AM62Lx supports integrated LDO SDIO_LDO (LDO internal to the processor, optimizing the design). Integrated SDIO_LDO can be used to power VDDSHV3 supply when MMC1 is configured for SD card interface. The output of the SD card supply control power switch described in the reset section below is connected as input to the SDIO_LDO (VDDA_3P3_SDIO). The output of SDIO_LDO is 3.3V during reset and allows changing to 1.8V when software is ready to change the supply voltage. The output of the SDIO_LDO is controlled by the V1P8_SIGNAL_ENA bit.
Make sure the recommended capacitor is connected to CAP_VDDSHV_MMC pin.
Processor MMC1 SD Card Detect (CD) and Write Protect (WP) signals are powered by VDDSHV1 supply rail (IO supply for GENERAL1 IO group). The recommendation is to connect the pullups for MMC1_SDCD, MMC1_SDWP from the SD card to the same supply rail VDDSHV1.
SD Card Detect (CD) input to the processor connects directly to ground when the SD card is inserted. A series resistor (100Ω) to limit the current in case the IO is configured as output due to programming error is recommended.
Processor MMC2 SD Card Detect (CD) and Write Protect (WP) signals are powered by VDDSHV4 supply rail or VDDSHV1 supply rail.
When SDIO_LDO is not used to power MMC1 or MMC2 IOs, see the Pin Connectivity Requirements section of the processor-specific data sheet to connect the VDDA_3P3_SDIO and CAP_VDDSHV_MMC pins.