Software Upgrade And Software Debug - SimCom SIM548C HD V1.01 Hardware Design

SIM548C Hardware Design
paid to the following requirements:
Synchronization between DTE and DCE.
When DCE powers on with the autobauding enabled, it is recommended to wait 2 to 3 seconds
before sending the first AT character. After receiving the "OK" response, DTE and DCE are
correctly synchronized.
Restrictions on autobauding operation
The serial port has to be operated at 8 data bits, no parity and 1 stop bit (factory setting).
The Unsolicited Result Codes like "RDY", "+CFUN: 1" and "+CPIN: READY" are not
indicated when you start up the ME while autobauding is enabled. This is due to the fact that
the new baud rate is not detected unless DTE and DCE are correctly synchronized as
described above.
Note: You can use AT+IPR=x;&W to set a fixed baud rate and save the configuration to
non-volatile flash memory. After the configuration is saved as fixed baud rate, the Unsolicited
Result Codes like "RDY" should be received from the serial port all the time that GSM part of
the module is power on.
Debug port
Two lines on Debug port
Only contains Data lines /TXD and /RXD
Debug Port only used for debugging. It cannot be used for CSD call, FAX call. And the
Debug port can not use multiplexing function. It doesnot support autobauding function.;
Debug port supports the communication rate as following:
9600, 19200, 38400, 57600, 115200bps(default)

3.9.2 Software upgrade and software debug

The TXD、RXD、DBG_TXD、DBG_RXD、GND must be connected to the IO connector when
user need to upgrade software and debug software, the TXD、RXD should be used for software
upgrade and the DBG_TXD 、 DBG_RXD for software debugging. The PWRKEY pin is
recommended to connect to the IO connector. The user also can add a switch between the
PWRKEY and the GND. The PWRKEY should be connected to the GND when the module is
upgrading software. Please refer to the following figures.
SIM548C_HD_V1.01
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09.05.2008