UM10208_2
© NXP B.V. 2007. All rights reserved.
User manual
Rev. 02 — 1 June 2007
284 of 362
1.
Introduction
The Secure Digital and Multimedia Card Interface (SD/MCI) is an interface between the
Advanced Peripheral Bus (APB) and multimedia and/or secure digital memory cards. It
consists of two parts:
•
The MCI adapter block provides all functions specific to the Secure Digital/MultiMedia
memory card, such as the clock generation unit, power management control,
command and data transfer.
•
The APB interface accesses the SD/MCI registers, and generates interrupt and DMA
request signals.
2.
Features of the SD/MCI
The following features are provided by the SD/MCI:
•
Conformance to Multimedia Card Specification v2.11.
•
Conformance to Secure Digital Memory Card Physical Layer Specification, v0.96.
•
Use as a multimedia card bus or a secure digital memory card bus host. It can be
connected to several multimedia cards, or a single secure digital memory card.
•
DMA transfers are supported through the GP DMA facility.
3.
SD/MMC card interface pin description
An additional signal is needed for the interface in some cases, a power control line called
MCIPWR. This function can be generated from any available pin, such as a GPIO, whose
level can be controlled by software.
4.
Functional overview
The MCI may be used as a multimedia card bus host or a secure digital memory card bus
host. Up to approximately 4 multimedia cards (limited by I/O pin specifications and board
loading) may be connected, or a single secure digital memory card.
4.1 Multimedia card
shows the multimedia card system.
UM10208
Chapter 23: SD/MMC interface
Rev. 02 — 1 June 2007
User manual
Table 322. SD/MCI Card Interface Pin Description
Pin Name
Type
Description
MCLK
Output
Clock output
MCMD
I/O
Command input/output.
MD3:0
I/O
Data lines. Only MD0 is used for Multimedia cards.