SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The eMMC/SD/SDIOi host controller has direct access to the internal data. This feature is called advanced DMA (ADMA). It follows a specific algorithm (ADMA2) defined by an instruction in memory that starts at an address previously loaded in the MMCHS_ADMASAL register before any data command issued to the MMC card. Only 32-bit address spacing is supported by the controller for data storage.
This mode is supported only by modules connected to the L3_MAIN interconnect. For more information and/or to check the value of the MMCHS_HL_HWINFO[0] MADMA_EN bit, see Section 27.1, eMMC/SD/SDIO Overview.
These instructions must be loaded by software in a 32-bit-addressed descriptor table in system memory, as shown in Figure 27-16. In this case the MMCHS_ADMASAL register is used as the program address pointer
Figure 27-16 ADMA Block Diagram Overview