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Example Summary

Configures different power policies based on the configuration of two input pins. Which allows user to prevent the device to indefinitely stay in SHUTDOWN mode since the serial wire debug (SWD) remain locked while the device is in SHUTDOWN mode.

After entering SHUTDOWN mode, the device will exit when a high level is detected on the wake-up pin. Then it will toggle LED2 for as many times as it has exited SHUTDOWN mode before (i.e. LED2 will toggle once the first time it wakes up, two times the second time it wakes-up and so on).

If a different power policy is selected via the configuration input pnis. The device will only remain in the selected power policy but will not wake-up via wake-up pin

The table below shows the power policy to be configured based on configuration input configuration.

config input 0 config input 1 Power Policy
High (default) High (default) SHUTDOWN
High (default) Low (pin grounded) STOP0
Low (pin grounded) High (default) STANDBY0
Low (pin grounded) Low (pin grounded) RUN0SLEEP0

Peripherals & Pin Assignments

Peripheral Pin Function
GPIOA PA18 Standard with Wake Input
GPIOA PA23 Standard Output
GPIOA PA0 Open-Drain Output
GPIOA PA14 Standard Input with internal pull-up
GPIOA PA28 High-Drive Input with internal pull-up
SYSCTL
EVENT
DEBUGSS PA20 Debug Clock
DEBUGSS PA19 Debug Data In Out

BoosterPacks, Board Resources & Jumper Settings

Visit LP_MSPM0L2228 for LaunchPad information, including user guide and hardware files.

Pin Peripheral Function LaunchPad Pin LaunchPad Settings
PA18 GPIOA PA18 J3_23
  • PA18 can be connected to S2 button to VCC with external pull-down
    • J1 ON Connect S2 button and external pull-down
    • J1 OFF Disconnect S2 button and external pull-down

  • PA18 can be connected to XDS-110 BSL_Invoke
    • J14 17:18 OFF Disconnect pin to XDS-110 BSL Invoke
PA23 GPIOA PA23 N/A
  • PA23 can be connected to VCC using R8 or to GND using C9
    • R8 and C9 are not soldered by default allowing the pin to be used for other functions

  • PA23 can be connected to LED4 Blue
    • J4 ON Connect to LED4 Blue
    • J4 OFF Disconnect from LED4 Blue
PA0 GPIOA PA0 J3_10
  • PA0 is 5V tolerant open-drain so it requires pull-up
    • J12 1:2 Use 3.3V pull-up
    • J12 2:3 Use 5V pull-up

  • PA0 can be connected to LED3
    • J2 ON Connect to LED3
    • J2 OFF Disconnect from LED3
PA14 GPIOA PA14 J3_26
  • PA14 has a capacitor to be used for LCDCAP1 functionality by default in Launchpad
    • Remove C50 if needed to use pin for other functions
PA28 GPIOA PA28 J7_34 N/A
PA20 DEBUGSS SWCLK N/A
  • PA20 is used by SWD during debugging
    • J14 15:16 ON Connect to XDS-110 SWDIO while debugging
    • J14 15:16 OFF Disconnect from XDS-110 SWDIO if using pin in application
PA19 DEBUGSS SWDIO N/A
  • PA19 is used by SWD during debugging
    • J14 13:14 ON Connect to XDS-110 SWDIO while debugging
    • J14 13:14 OFF Disconnect from XDS-110 SWDIO if using pin in application

Device Migration Recommendations

This project was developed for a superset device included in the LP_MSPM0L2228 LaunchPad. Please visit the CCS User’s Guide for information about migrating to other MSPM0 devices.

Low-Power Recommendations

TI recommends to terminate unused pins by setting the corresponding functions to GPIO and configure the pins to output low or input with internal pullup/pulldown resistor.

SysConfig allows developers to easily configure unused pins by selecting Board→Configure Unused Pins.

For more information about jumper configuration to achieve low-power using the MSPM0 LaunchPad, please visit the LP-MSPM0L2228 web page.

Example Usage

Compile, load and run the example. Rising edge in S2 will wake device from SHUTDOWN state and LED2 blinks equal to the number of times the device has been woken up.