REL0.1
Page 44 of 52
Snapdragon 820 SMARC SOM Hardware User Guide
iWave Systems Technologies Pvt. Ltd.
Pin
No
Signal Name
Signal Type/
Termination
Description
18
GND
Power
Ground.
19
-
-
Default NC.
Note: Optionally this pin is connected to CPU ACK
pin (AE17) through resistor and default not
populated.
20
GND
Power
Ground.
2.9.2
Debug UART Header
The APQ8096 CPU’s BLSP8 UART is used as Debug UART. Which will give the boot long and terminal access to the CPU.
In Snapdragon 820 SMARC SOM BLSP8 UART is connected to SER3 UART channel of SMARC Edge connector. But also
as an option to connect to J5 conn
ector. FTDI’s UART to USB smart cable (
TTL-232R-RPI)
can be sued for connecting to
Host Computer for debugging.
Table 7: Debug UART Header Pin Out
Pin
No
Pin Name
Signal Name
Signal Type/
Termination
Description
1
TX
BLSP8_UART_TX
O, 3.3V CMOS0
UART8 Transmit
2
RX
BLSP8_UART_RX
I, 3.3V CMOS0
10K PD
UART8 Receive
3
GND
GND
Power
Ground
2.9.3
Battery Connector
The Snapdragon 820 SMARC is default powered with SMARC Edge connector pins, but it as option to connect battery
as a backup power supply source with On SOM Battery Charging controller IC. 3.7 to 4.5V battery can be connected
to J2 connector. J2 is placed on to side of PCB and J2 pinout is as given below:
Number of Pins
- 3
Connector Part
- BM03B-ACHSS-GAN-TF(LF)(SN) from JST Sales America Inc.
Mating Connector
- ACHR-03V-S from JST Sales America Inc.
Table 8: Battery Connector Pin Out
Pin
No
Pin Name
Signal Name
Signal Type/
Termination
Description
1
VBATT
VBATT
I, 3.6 ~ 4.35V
Battery input pin
2
BATT_THERM
BATT_THERM
I,
Battery thermal sense pin.
GND
GND
Power
Ground