UM10208_2
© NXP B.V. 2007. All rights reserved.
User manual
Rev. 02 — 1 June 2007
286 of 362
NXP Semiconductors
UM10208
Chapter 23: LPC2800 SD/MMC
•
MD3:0 Bidirectional data signals
4.3 MCI adapter
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
4.3.1 Adapter register block
The adapter register block contains all MCI/SD registers. This block also generates the
signals that clear the static flags in the multimedia card. The clear signals are generated
when a 1 is written into the corresponding bit location of the MCIClear register.
4.3.2 Control unit
The control unit contains the power management functions and the clock divider for the
memory card clock.
There are three power phases:
•
Power-off
•
Power-up
•
Power-on
Fig 33. MCI adapter
MULTIMEDIA CARD INTERFACE
ADAPTER
REGISTERS
CONTROL
UNIT
FIFO
COMMAND
PATH
DATA PATH
APB BUS
APB
INTERFACE
MCMD
MCLK
MD [3:0]
MCIPWR
(from GPIO)