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XT2 option in the MSP430 family guide

Daniel Gore
Prodigy 90 points
Other Parts Discussed in Thread: MSP430G2231

The part selection guide to the MSP430 family does not clearly tell me which device contains the internal XT2 16MHz oscillator. I am using the LaunchPad which comes with the MSP430G2231/2211 devices, but notes in the family user guide (p.282) seem to indicate that these two devices have no XT2 support.

My question is, Which devices in the MSP430 family DO contain the internal (16MHz) XT2 source?

-D.Gore

  • 0
    TI__Genius 10830 points

    Let's separate our terms.  These are clock sources and clock signals for the MSP430:  The clock signals are generated from the clock sources.

    These are the clock sources for the MSP430G2231

    External Crystal Oscillator (XT1, LFXT1)
    Interal digitally controlled oscillator (DCO)
    Internal Very-Low-Power Low-Frequency Oscillator (VLO)

    These are the MSP430 clock signals.

    Auxiliary clock (ACLK)
    Main clock (MCLK)
    Sub-Main clock (SMCLK)

    In your case, I suggest you use the DCO configured to 16 MHz to be the source of the MCLK.  If you want an external source for the clock signals, then we can reconsider devices with the external XT2.

  • 0
    Guru 227245 points

    Daniel Gore said:
    The part selection guide to the MSP430 family does not clearly tell me which device contains the internal XT2 16MHz oscillator

    Indeed. The 2x family users guide does (in the clock system section).
    However, none of the G2x series devices supports XT2 or even a high-speed XT1.

    I think you also were confused by the term 'oscillator' regarding the XT1/XT2. It refers to the internal oscillation circuit to drive an external crystal. Wihtotu an external crystal, these 'internal oscillators' won't oscillate at all. The crystal is the frequency-controlling part.

    But every MSP has a completely self-contained and purely internal oscillator: the DCO.
    Some MSPs also have VLO and REFO, and there's also MODOSC. And the DCO is programmable for a selection of discrete frequencies. Which ones exactly are available, however, depends on the individual MSP, so individual calibration is required (and in some cases factory-provided)

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