A.3. MMC and SD card interface

The MMC/SD card socket is positioned on the front panel of the enclosure, see Figure 3.2 for the connector location.

Caution

The MMC or SD card must be inserted into the front panel socket with the contacts facing down.

Figure A.3 shows the pin numbering and signal assignment. In addition, the socket contains switches that are operated by card insertion that provide signaling on the CARDINx and MCI_WPROT signals.

Figure A.3. MMC/SD card socket pin numbering

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The MMC card uses seven pins, and the SD card uses all nine pins. The additional pins are located as shown in Figure A.3 with pin 9 next to pin 1 and pins 7 and 8 spaced more closely together than the other pins. Figure A.4 shows an MMC card, with the contacts face up.

Figure A.4. MMC card

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Table A.2 lists the signal assignments.

Table A.2. Multimedia Card interface signals

Pin SignalFunction SDFunction MCI
1MCIxDATA3Data Chip select
2MCIxCMDCommand/responseData in
3GNDGroundGround
4MCIVDDxSupply voltageSupply voltage
5MCICLKxClockClock
6GNDGroundGround
7MCIxDATA0Data 0Data out
8MCIxDATA1Data 1NC
9MCIxDATA2Data 2 NC
10 (DET A)CARDINxCard insertion detectCard insertion detect
11 (DET B)WPROTxWrite protect status Write protect status

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