SLAAE75B March   2023  – May 2023 MSPM0L1105 , MSPM0L1106 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 MSPM0L Hardware Design Checklist
  5. 2 Power Supplies in MSPM0L 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 Clock Output (CLK_OUT)
    3. 4.3 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
    2. 6.2 OPA Design Considerations
    3. 6.3 DAC Design Considerations
    4. 6.4 COMP Design Considerations
    5. 6.5 GPAMP Design Considerations
    6. 6.6 LCD 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
    4. 8.4 Open-Drain GPIOs Enable 5-V Communication Without a Level Shifter
    5. 8.5 Communicate With 1.8V Devices Without a Level Shifter
    6. 8.6 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. 10Bootloader
    1. 10.1 Bootloader Introduction
    2. 10.2 Bootloader Hardware Design Considerations
      1. 10.2.1 Physical Communication interfaces
      2. 10.2.2 Hardware Invocation
  14. 11References
  15. 12Revision History

8.6 Unused Pins Connection

All microcontrollers are designed for a variety of applications and often a particular application does not use 100% of the MCU resources.

To increase EMC performance, do not leave unused clocks, counters, and I/Os free or floating; for example, set I/Os to 0 or 1 (pullup or pulldown on unused I/O pins) and disable unused features.

Table 8-3 Connection of Unused Pins
Pin Potential Comment
PAx Open Set corresponding pin functions to GPIO (PINCMx.PF = 0x1) and configure unsused pins to output low or input with internal pullup or pulldown resistor.
OPAx_IN0- Open This pin is high-impedance
NRST VDD NRST is an active-low reset signal; this must be pulled high to VCC or the device does not start.
Note:
  • To reduce leakage, it is advisable to configure the I/O as an analog input or to push-pull and to set it to “0”.
  • BSL invoke pin must be pulled down to avoid entering BSL mode after reset.