CLM920_AC3 Module Hardware Usage Guide
Shanghai Yuge Information Technology co., LTD
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Figure 3-15 Level conversion chip circuit
3.6.2 Debug serial port
The 11th and 12th pins of the module are debug serial port pins, and the debug serial port
supports 115200bps baud rate. It is used for Linux control and log printing. It can reserve test
points for module debugging. Please do not leave it floating.
Table 3-12 Debugging serial port pin definitions
Pin
Signal
name
I/O Description
Param
eter
Level value (V)
Rema
rks
Min Typical Max
11
DBG_RXD DI
UART data
reception
VIH
1.2
1.8
2
VIL
-0.3
0.6
12
DBG_TXD DO
UART data
transmission
VOH
1.35 1.8
2
VOL
0
0.45
3.6.3 RI Signal interface
The CLM920 AC3 module supports the serial sleep wake-up function, and the RI pin can
be used as an interrupt to wake up the host.
RI:
The RI pin can wake up the host as an interrupt.
The RI pin idle state is low. When a short message or voice incoming call is received, the
RI outputs a rectangular wave with a period of 500ms (high level for 250ms, low level for
250ms) to wake up the host.
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