SDAA018 December   2025 MSPM0H3216

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 MSPM0H Hardware Design Check List
  5. 2 Power Supplies in MSPM0H Devices
    1. 2.1 Digital Power Supply
    2. 2.2 Analog Power Supply
    3. 2.3 Built-in Power Supply and Voltage Reference
    4. 2.4 Recommended Decoupling Circuit for Power Supply
  6. 3 Reset and Power Supply Supervisor
    1. 3.1 Digital Power Supply
    2. 3.2 Power Supply Supervisor
  7. 4 Clock System
    1. 4.1 Internal Oscillators
    2. 4.2 External Oscillators
    3. 4.3 External Clock Output (CLK_OUT)
    4. 4.4 Frequency Clock Counter (FCC)
  8. 5 Debugger
    1. 5.1 Debug Port Pins and Pinout
    2. 5.2 Debug Port Connection With Standard JTAG Connector
  9. 6 Key Analog Peripherals
    1. 6.1 ADC Design Considerations
  10. 7 Key Digital Peripherals
    1. 7.1 Timer Resources and Design Considerations
    2. 7.2 UART and LIN Resources and Design Considerations
    3. 7.3 I2C and SPI Design Considerations
  11. 8 GPIOs
    1. 8.1 GPIO Output Switching Speed and Load Capacitance
    2. 8.2 GPIO Current Sink and Source
    3. 8.3 High-Speed GPIOs (HSIO)
    4. 8.4 Communicate With a 1.8V/3.3V Device Without a Level Shifter
    5. 8.5 Unused Pins Connection
  12. 9 Layout Guides
    1. 9.1 Power Supply Layout
    2. 9.2 Considerations for Ground Layout
    3. 9.3 Traces, Vias, and Other PCB Components
    4. 9.4 How to Select Board Layers and Recommended Stack-up
  13. 10Summary
  14. 11References

4.2 External Oscillators

For applications that require even higher clock accuracy across devices and temperature, external oscillators can be used. LFXT can replace LFOSC, and HFXT can replace SYSOSC.

Low-Frequency Crystal Oscillator (LFXT)

The LFXT is an ultra-low power crystal oscillator that supports driving a standard 32.768kHz watch crystal. To use the LFXT, populate a watch crystal between the LFXIN and LFXOUT pins. Place loading capacitors on both LFXIN and LFXOUT pins to circuit ground (VSS). Size the crystal load capacitors according to the specifications of the crystal being used. A variety of crystal types are supported through a programmable drive strength mechanism. For the layout advice, refer to Section 9.

MSPM0H LFXT CircuitFigure 4-2 MSPM0H LFXT Circuit

LFCLK_IN (Digital Clock)

The LFXT circuit can be bypassed and a 32.76kHz typical frequency digital clock can be brought into the device to use as the LFCLK source. LFCLK_IN and LFXT are mutually exclusive and must not be enabled at the same time.

LFCLK_IN is compatible with digital square-wave CMOS clock inputs with a typical duty cycle of 50%. Users can check for a valid clock signal on LFCLK_IN by enabling the LFCLK monitor. By default, the LFCLK monitor checks LFCLK_IN if the LFXT was not started.

High-Frequency Crystal Oscillator (HFXT)

The high frequency crystal oscillator (HFXT) can be used with standard crystals and resonators in the 4 to 48MHz range to generate a stable high-speed reference clock for the system.

To use the HFXT, populate a crystal or resonator between the HFXIN and HFXOUT pins. Place loading capacitors on both pins to circuit ground (VSS). Size the crystal load capacitors according to the specifications of the crystal being used. A programmable HFXT startup time is provided with 64µs resolution. For layout advice, refer to Section 9.

MSPM0H HFXT CircuitFigure 4-3 MSPM0H HFXT Circuit

HFCLK_IN (Digital clock)

Users can bypass the HFXT circuit and bring in a 4 to 48MHz typical frequency digital clock into the device to use as the HFCLK source instead of HFXT. HFCLK_IN and HFXT are mutually exclusive and must not be enabled at the same time.

HFCLK_IN is compatible with digital square wave CMOS clock inputs with a typical duty cycle of 50%.