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Checking of serial port of msp430

I am working  with msp430. If I want to check whether its serial port is working or not  and I connect its serial port to oscilloscope. What kind of waveform should I get?  A continuous square waveform or bunch of  square pulses repeating itself after a time duration.

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  • Serial port is usually a straight high signal unless something is transmitted. During transmission you'll have at least one short low pulse (length of one bit, the start bit) and 8 data bits that may be low or high dependein on data, followed by at least on bit duration of high. The length of a bit depends on the baudrate.

    Keep in mind that RS232 signals are inverted and symmetrical. So a 'low' is 0V on the MSP/TTL signals, but 3V to 12V on RS232, while a 'high' is VCC on the MSP and -3 to -12V on RS232 (you need a transceiver such as the MAX2323 to connec the MSP to the PC COM port)