User guide

M80 EVB User Guide
M80_EVB_UGD_V1.2 - 26 -
Figure 25: Test points of main port
The main port can be used for upgrading firmware. The PWRKEY pin must be pulled down
before the firmware upgrade. For more details about upgrading firmware with UART, please refer
to chapter 5.5.1.
3.6.2. Auxiliary UART and Debug UART
When Auxiliary UART port and Debug Port are used to communicate data between PC and the
module, a RS_232 level shifter must be inserted between them. The reference design is same as
the main port. Auxiliary UART port is used for AT command only, since it does not support
GPRS data, CSD FAX, and Multiplexing function, etc. Debug Port is only used for firmware
debugging and its baud rate must be configured as 460800bps. For the circuit design of Auxiliary
UART port and Debug Port, please refer to document [3] and document [5].
Figure 26: Auxiliary UART port and Debug Port
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