The SDMMC_ARGR register contains a 32-bit command argument, which is sent to a card as part of a command message.
CMDARG | Command argument. These bits can only be written by firmware when CPSM is disabled (CPSMEN = 0). Command argument sent to a card as part of a command message. If a command contains an argument, it must be loaded into this register before writing a command to the command register. |