1 power control register (mci power - 0xe008 c000), 2 clock control register (mciclock - 0xe008 c004), Nxp semiconductors – NXP Semiconductors LPC24XX UM10237 User Manual
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UM10237_4
© NXP B.V. 2009. All rights reserved.
User manual
Rev. 04 — 26 August 2009
564 of 792
NXP Semiconductors
UM10237
Chapter 21: LPC24XX SD/MMC card interface
[1]
Reset Value reflects the data stored in used bits only. It does not include reserved bits content.
6.1 Power Control Register (MCI Power - 0xE008 C000)
The MCIPower register controls an external power supply. Power can be switched on and
off, and adjust the output voltage.
shows the bit assignment of the
MCIPower register.
The active level of the MCIPWR (Power Supply Enable) pin can be selected by bit 3 of the
SCS register (see
Section 3–7.1 “System Controls and Status register (SCS - 0xE01F
C1A0)” on page 36
for details).
When the external power supply is switched on, the software first enters the power-up
phase, and waits until the supply output is stable before moving to the power-on phase.
During the power-up phase, MCIPWR is set HIGH. The card bus outlets are disabled
during both phases.
Note: After a data write, data cannot be written to this register for three MCLK clock
periods plus two PCLK clock periods.
6.2 Clock Control Register (MCIClock - 0xE008 C004)
The MCIClock register controls the MCICLK output.
shows the bit
assignment of the clock control register.
MCIMask0
Interrupt 0 mask register.
R/W
22
0x000000
0xE008 C03C
MCIFifoCnt
FIFO Counter.
RO
15
0x0000
0xE008 C048
MCIFIFO
Data FIFO Register.
R/W
32
0x00000000 0xE008 C080
to
0xE008 C0BC
Table 490. Summary of MCI registers
Name
Description
Access Width Reset
Value
[1]
Address
Table 491: Power Control register (MCIPower - address 0xE008 C000) bit description
Bit
Symbol
Value Description
Reset
Value
1:0
Ctrl
00
Power-off
00
01
Reserved
10
Power-up
11
Power-on
5:2
-
Reserved, user software should not write ones to
reserved bits. The value read from a reserved bit is not
defined.
NA
6
OpenDrain
MCICMD output control.
0
7
Rod
Rod control.
0
31:8
-
Reserved, user software should not write ones to
reserved bits. The value read from a reserved bit is not
defined.
NA