SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The CHMMCSD configuration header contains settings specific to the high-speed MMC/SD/SDIO host controller (MMCHS). For more information, see Chapter 25, eMMC/SD/SDIO. Table 32-52 describes the fields.
| Offset | Field | Description |
|---|---|---|
| 0000h | Section key | Key used for section verification C0C0C0C4h |
| 0004h | Valid | Enables/disables the section: |
| 00h: Disable | ||
| Other: Enable | ||
| 0005h | Reserved | |
| 0008h | CLKD | Functional clock divisor MMCHS_SYSCTL[15:6] CLKD = 0x0: FCLK/1 0x1: FCLK/1 0x2: FCLK/2 … 0x3FF: FCLK/1023 0xFFFF FFFF: Do not modify clock divisor |
| 000Ch | MMCHS interface bus width | Configure the MMCHS interface bus width according to the field value : |
| 1: Configured to 1 bit (SDR) | ||
| 2: Configured to 4 bits (SDR) | ||
| 4: Configured to 8 bits (SDR)(1) | ||
| 8: Configured to 4 bits (DDR)(1) | ||
| 16: Configured to 8 bits (DDR)(1) | ||
| 0xFFFF FFFF: Do not update bus width. | ||
| Others: Reserved |
The ROM code provides a booting parameter structure to the initial software (see Section 32.3.8.4, Image Execution). This structure contains a field that indicates whether the configuration header items have been correctly processed. For a CHMMCSD item, if the MMCHS_SYSCTL and bus width fields are set to 0xFFFF FFFF, the booting parameters report that the CHMMCSD section has not been executed, regardless of the value of the Valid field.