UM10237_2 © NXP B.V. 2008. All rights reserved.
User manual Rev. 02 — 19 December 2008 553 o f 792
NXP Semiconductors UM10237
Chapter 21: LPC24XX SD/MMC card interface

5.2.1 Secure digital memory card bus signals

The following signals are used on the secure digital memory card bus:
CLK Host to card clock signal
CMD Bidirectional command/response signal
DAT[3:0] Bidirectional data signals
5.3 MCI adapter
Figure 21–106 shows a simplified block diagram of the MCI adapter.
The MCI adapter is a multimedia/secure digital memory card bus master that provides an
interface to a multimedia card stack or to a secure digital memory card. It consists of five
subunits:
Adapter register block
Control unit
Command path
Data path
Data FIFO
Fig 105. Secure digital memory card connection
SECURE
DIGITAL
MEMORY CARD
CONTROLLER
SECURE
DIGITAL
MEMORY CARD
CLK
CMD
D[3:0]
Fig 106. MCI adapter
MULTIMEDIA CARD INTERFACE
ADAPTER
REGISTERS
CONTROL
UNIT
FIFO
COMMAND
PATH
DATA PATH
APB BUS APB
INTERFACE
MCICMD
MCICLK
MCIDATA [3:0]
MCIPWR