MCUXpresso_LPC55S69/boards/lpcxpresso55s69/driver_examples/ctimer/simple_match_interrupt/cm33_core0

Overview

The Simple Match Interrupt project is to demonstrate usage of the SDK CTimer driver with interrupt callback functions In this example the upon match and IO pin connected to the LED is toggled and the timer is reset, so it would generate a square wave. When the number of times of entering the interrupt callback function is greater than matchUpdateCount, matchValue will be divided by 2, and matchUpdateCount will be multiplied by 2. When matchUpdateCount == 0XFF, matchUpdateCount and matchValue will return to the original settings. With an interrupt callback the match value is changed frequently in such a way that the frequency of the output square wave is increased gradually.

SDK version

• Version: 2.15.000

Toolchain supported

• IAR embedded Workbench 9.40.1
• Keil MDK 5.38.1
• GCC ARM Embedded 12.2
• MCUXpresso 11.8.0

Hardware requirements

• Micro USB cable
• LPCXpresso55s69 board
• Personal Computer

Board settings

No special settings are required.

Prepare the Demo

Note: MCUXpresso IDE project default debug console is semihost

1. Connect a micro USB cable between the host PC and the LPC-Link USB port (P6) on the target board.
2. Open a serial terminal with the following settings:
   • 115200 baud rate
   • 8 data bits
   • No parity
   • One stop bit
   • No flow control
3. Download the program to the target board.
4. Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.

Running the demo

The log below shows example output of the CTimer simple match demo using interrupts in the terminal window:

CTimer match example to toggle the output. 
This example uses interrupt to change the match period.

You can see the blue led and green led will blinking alternating frequently and then return to the original status.