SOM-9X20 User Manual
13
A.3.3.
RTC Battery Connector
The SOMDB2 carrier board is equipped with an onboard RTC battery connector used for connecting the
external cable battery that provides power to the 32.768KHz crystal oscillator for Real Time Clock (RTC). The
RTC battery connector is labeled as “RTC1”.
Figure 16:
RTC battery connector diagram
A.3.4. Micro SD Card Slot
The SOMDB2 carrier board comes with a Micro SD card slot located on the front panel with support for a
maximum storage capacity of 64GB. The pinouts of the Micro SD card slot are show below.
Table 3: Micro SD card slot pinouts
Pin
Signal
1
SD_DAT2
2
SD_DAT3
3
SD_CMD
4
SD_VDD
5
SD_CLK
6
GND
7
SD_DAT0
8
SD_DAT1
9
SD_CD-
BR203
2
+
RTC1
BR2032
+
BR203
2
+
1
SD
1
Figure 17: Micro SD card slot diagram
