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Example Summary

Demonstrates Frequency Clock Counter (FCC). The FCC is configured to count the number of SYSOSC periods that have occurred between two LFCLK rising-edge to rising-edge periods.

Once the FCC is done counting the period, the number of measured counts is compared against pre-computed max and min expected values to determine if SYSOSC is within the expected frequency range.

The red LED is turned on if the FCC counter is within the expected range or will remain off if the test fails.

The example is also configured to output SYSOSC via CLK_OUT to allow monitoring the clock externally.

Peripherals & Pin Assignments

Peripheral Pin Function
GPIOA PA0 Open-Drain Output
GPIOA PA1 Open-Drain Output
SYSCTL PA10 CLK OUT
EVENT
DEBUGSS PA20 Debug Clock
DEBUGSS PA19 Debug Data In Out

BoosterPacks, Board Resources & Jumper Settings

Visit LP_MSPM0L1306 for LaunchPad information, including user guide and hardware files.

Pin Peripheral Function LaunchPad Pin LaunchPad Settings
PA0 GPIOA PA0 J1_10
  • PA0 is 5V tolerant open-drain so it requires pull-up
    • J10 2:3 Use 3.3V pull-up
    • J10 1:2 Use 5V pull-up

  • PA0 can be connected to LED1
    • J2 ON Connect to LED1
    • J2 OFF Disconnect from LED1
PA1 GPIOA PA1 J1_9
  • PA1 is 5V tolerant open-drain so it requires pull-up
    • J19 2:3 Use 3.3V pull-up
    • J9 1:2 Use 5V pull-up
PA10 SYSCTL CLK_OUT J4_36 N/A
PA20 DEBUGSS SWCLK J2_13
  • PA20 is used by SWD during debugging
    • J101 15:16 ON Connect to XDS-110 SWCLK while debugging
    • J101 15:16 OFF Disconnect from XDS-110 SWCLK if using pin in application
PA19 DEBUGSS SWDIO J2_17
  • PA19 is used by SWD during debugging
    • J101 13:14 ON Connect to XDS-110 SWDIO while debugging
    • J101 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_MSPM0L1306 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-MSPM0L1306 User’s Guide.

Example Usage

Compile, load and run the example. LED1 should turn on after executing if the FCC counter is within the expected range. USER_TEST_PIN GPIO will mimic the behavior of the LED pin on the BoosterPack header and can be used to verify the LED behavior. Confirm FCC measurement by measuring SYSOSC frequency via CLK_OUT.