Hardware Design V1.0

NB-IoT Module Series
BC95 Hardware Design
BC95_Hardware_Design Confidential / Released 21 / 45
3.7. SWD Interface
The module provides one Serial Wire Debug (SWD) interface for firmware upgrading. It is recommended
to reserve SWD interface in order to upgrade firmware.
Table 8: Pin Definition of SWD Interfaces
The following figure is a reference design for SWD interface.
VDD_EXT
SWD_CLK
RESET
TDI
TMS
TCK
Module
(DCE)
GND
RTCK
JTAG_20 PIN
VCC
TRST
TDO
RESET
NC
NC
GND
GND
GND
GND
NC
GND
GND
GND
GND
GND
SWD_DATA
Figure 8: Reference Design for SWD Interface
3.8. UART Interfaces
The module provides two UART ports: main port and debug port. The module is designed as a DCE (Data
Communication Equipment), following the traditional DCE-DTE (Data Terminal Equipment) connection.
The main port:
 TXD: Send data to RXD of DTE.
 RXD: Receive data from TXD of DTE.
 RI: Ring indicator (when the SMS, data of the module are coming, the module will output signal to
inform DTE).
Interfaces
Name
Pin NO.
Description
SWD
SWD_DATA
3
Serial wire data signal
SWD
SWD_CLK
4
Serial wire clock signal
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