Microcontrollers User manual

UM10237_2 © NXP B.V. 2008. All rights reserved.
User manual Rev. 02 — 19 December 2008 553 of 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