Smart Module Series
SC200L_Series(Dual-band Wi-Fi)_Hardware_Design 43 / 111
3.9. UART Interfaces
The module provides the following two UART interfaces:
⚫
UART0
: 4-wire UART interface, supports RTS and CTS hardware flow control, up to 3.25 Mbps
⚫
Debug UART
: 2-wire UART interface, used for debugging by default
The following table shows the pin definition of UART interfaces.
Table 13: Pin Definition of UART Interfaces
UART0 is a 4-wire UART interface with 1.85 V power domain. A level translator should be used if your
application is equipped with a 3.3 V UART interface.
VCCA
VCCB
OE
A1
A2
A3
A4
GND
B1
B2
B3
B4
LDO1_1V85
UART 0_RTS
UART0_RXD
UART 0_CTS
UART0_TXD
RXD_3.3 V
CTS_3.3 V
TXD_3.3 V
VDD_3.3 V
TXS0104EPWR
C1
100 pF
C2
U1
100 pF
RTS_3.3 V
Figure 15: Reference Circuit with Level Translator Chip (for UART0)
Pin Name
Pin No.
I/O
Description
Comment
UART0_TXD
34
DO
UART0 transmit
1.85 V power domain.
If not used, keep these pins open.
UART0_RXD
35
DI
UART0 receive
UART0_CTS
36
DI
DCE clear to send
UART0_RTS
37
DO
DCE request to send
DBG_RXD
93
DI
Debug UART receive
DBG_TXD
94
DO
Debug UART transmit