Application Note
6 of 19
002-27376 Rev. *A
2021-06-15
Getting Started with CXPI Transceiver S6BT112A
Hardware configuration
3
Hardware configuration
3.1
Master node connection example
When using S6BT112A as a master node, pull down the master / slave switching pin (SELMS: 8 pin). The baud
rate clock, generated by the master node using the MCU timer, is the input to the clock input pin (CLK: 3 pin).
Note that, the MCU UART baud rate and timer output need not be synchronized. The TXD and RXD pins are
connected to the MCU's UART pin, and the BUS pin is pulled up to V
BATTERY
with a 1-k
Ω resistor. The NSLP pin
controls the S6BT112A mode transition between the Sleep mode and the Normal mode after power-on with the
GPIO of the MCU.
shows the master node circuit connection (example using Traveo II MCU).
220 pF
+5 V or +3.3 V
S6BT112A
RXD
NSLP
CLK
TXD
SELMS
BAT
BUS
GND
1
2
3
4
8
7
6
5
GND
+B
BUS
GND
GND
GND
GND
10 k
Ω
10 µF
10 k
Ω
0.1 µF
GND
CYT2B9
VDDD
GND
P20-5/
CXPI3_RX
P12-5/
GPIO
P14-6/
PWM
P20-6/
CXPI3_TX
R4
R3
D1
GND
R6
1N4148
D3
1 k
Ω
TVII
R2
10 k
Ω
Figure 2
Example of master node connection consisting of Traveo II MCU and S6BT112A
3.2
Slave node connection example
When using S6BT112A as a slave node, pull up the master / slave switching pin (SELMS: 8 pin). The clock output
pin (CLK: 3 pin) is connected to the MCU external interrupt pin, GPIO input pin, etc. It is used to detect the
wakeup pulse in the Sleep mode, or to measure the communication baud rate in the Normal mode and the
baud rate on the MCU side. Connect the TXD and RXD pins to the MCU's UART pin. The NSLP pin controls the
S6BT112A mode transition between the Sleep mode and the Normal mode after power on with the GPIO of the
MCU.
