40.1 Overview

The SD/MMC Host Controller (SDHC) supports the embedded MultiMedia Card (e.MMC) Specification, the SD Memory Card Specification, and the SDIO Specification. It is compliant with the SD Host Controller Standard specifications.

The SDHC includes the register set defined in the "SD Host Controller Simplified Specification V3.00" and additional registers to manage e.MMC devices and enhanced features.

The SDHC is clocked by up to three clocks (bus clock, SDHC core clock, and a slow clock for certain functions). Both the MCLK and GCLK must be configured before the SDHC can be used.