SD Card Subsystem
The expansion board contains a micro SD card slot at J5 attached to the bottom side. See
Expansion Board Interfaces
for the location of the SD card slot.
The SD card interface is sourced from the Intel Joule module and routed to an NXP IP4856CX25 level shifter. The level shifter allows for the support of both 1.8 volt and 2.9 volt cards. The output of the level shifter is routed directly to the micro SD card connector.
The micro SD card connector power is sourced from the +3.3 volt buck/boost regulator.
Refer to the micro SD card specifications for electrical and power requirements. Refer to the NXP IP4856CX25 datasheet for the SD card interface signal specifications. The power from the level shifter can support a maximum current of 100 mA and has a supply voltage of 2.9 V.
Micro SD Card Connector Pinout
Pin #
|
Net Name
|
Direction
|
Signal Description
|
1 |
SDCARD_D2_CONN |
Bidirectional |
Data lane 2
|
2 |
SDCARD_D3_CONN |
Bidirectional |
Data lane 3
|
3 |
SDCARD_CMD_CONN |
Bidirectional | |
4 |
+V3P3V_MICROSD |
Output |
+2.9 volt supply to SD card
|
5 |
SDCARD_CLK_CONN |
Output | |
6 |
GND |
Ground |
Ground
|
7 |
SDCARD_D0_CONN |
Bidirectional |
Data lane 0
|
8 |
SDCARD_D1_CONN |
Bidirectional |
Data lane 1
|