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User's Guide
SPRUE30B – September 2006
Multimedia Card (MMC)/Secure Digital (SD) Card Controller
1Introduction
This document describes the multimedia card (MMC)/secure digital (SD) card controller in the TMS320DM644x Digital Media
1.1Purpose of the Peripheral
A number of applications use the multimedia card (MMC)/secure digital (SD) card to provide removable data storage. The MMC/SD card controller provides an interface to external MMC and SD cards. The communication between the MMC/SD card controller and MMC/SD card(s) is performed according to the MMC/SD protocol.
1.2Features
The MMC/SD card controller has the following features:
∙Supports interface to multimedia cards (MMC)
∙Supports interface to secure digital (SD) memory cards
∙Ability to use the MMC/SD protocol
∙Programmable frequency of the clock that controls the timing of transfers between the MMC/SD controller and memory card
∙
∙Signaling to support enhanced direct memory access (EDMA) transfers (slave)
∙20 MHz maximum clock to MMC (specification 3.31)
∙50 MHz maximum clock to SD (specification version 1.1)
1.3Functional Block Diagram
The MMC/SD card controller transfers data between the ARM and the EDMA controller on one side and the MMC/SD card on the other side, as shown in Figure 1. This means you have a choice of performing data transfers using the CPU or EDMA as a mechanism to move data between the device memory and the FIFO. The ARM and the EDMA controller can read from or write to the data in the card by accessing the registers in the MMC/SD controller.
SPRUE30B | Multimedia Card (MMC)/Secure Digital (SD) Card Controller | 9 |