The supported board list:
- SAM D21/R21/L21/L22/DA1/C21/HA1G16A Xplained Pro
- SAM D11 Xplained Pro
In this use case, the TCC will be used as a timer, to generate overflow and compare match callbacks. In the callbacks the on-board LED is toggled.
The TCC module will be set up as follows:
- GCLK generator 1 (GCLK 32K) clock source
- Use double buffering write when set top, compare, or pattern through API
- No dithering on the counter or compare
- Prescaler is divided by 64
- GCLK reload action
- Count upward
- Don't run in standby
- No waveform outputs
- No capture enabled
- Don't perform one-shot operations
- No event input enabled
- No event action
- No event generation enabled
- Counter starts on 0
- Counter top set to 2000 (about 4s) and generate overflow callback
- Channel 0 is set to compare and match value 900 and generate callback
- Channel 1 is set to compare and match value 930 and generate callback
- Channel 2 is set to compare and match value 1100 and generate callback
- Channel 3 is set to compare and match value 1250 and generate callback
Quick Start
Prerequisites
For this use case, XOSC32K/OSC32K should be enabled and available through GCLK generator 1 clock source selection. Within Atmel Software Framework (ASF) it can be done through modifying conf_clocks.h. See System Clock Management Driver for more details about clock configuration.
Code
Add to the main application source file, outside of any functions:
Copy-paste the following callback function code to your user application:
Copy-paste the following setup code to your user application:
{
#if (SAMR30E)
#else
#endif
config_tcc.counter.period = 2000;
config_tcc.compare.match[0] = 900;
config_tcc.compare.match[1] = 930;
config_tcc.compare.match[2] = 1100;
config_tcc.compare.match[3] = 1250;
}
{
TCC_CALLBACK_CHANNEL_0);
TCC_CALLBACK_CHANNEL_1);
TCC_CALLBACK_CHANNEL_2);
TCC_CALLBACK_CHANNEL_3);
}
Add to user application initialization (typically the start of main()
):
Workflow
- Create a module software instance structure for the TCC module to store the TCC driver state while it is in use.
- Note
- This should never go out of scope as long as the module is in use. In most cases, this should be global.
- Configure the TCC module.
- Create a TCC module configuration struct, which can be filled out to adjust the configuration of a physical TCC peripheral.
- Initialize the TCC configuration struct with the module's default values.
- Note
- This should always be performed before using the configuration struct to ensure that all values are initialized to known default settings.
- Alter the TCC settings to configure the GCLK source, prescaler, period, and compare channel values.
#if (SAMR30E)
#else
#endif
config_tcc.counter.period = 2000;
config_tcc.compare.match[0] = 900;
config_tcc.compare.match[1] = 930;
config_tcc.compare.match[2] = 1100;
config_tcc.compare.match[3] = 1250;
- Configure the TCC module with the desired settings.
- Enable the TCC module to start the timer.
- Configure the TCC callbacks.
- Register the Overflow and Compare Channel Match callback functions with the driver.
TCC_CALLBACK_CHANNEL_0);
TCC_CALLBACK_CHANNEL_1);
TCC_CALLBACK_CHANNEL_2);
TCC_CALLBACK_CHANNEL_3);
- Enable the Overflow and Compare Channel Match callbacks so that it will be called by the driver when appropriate.
Use Case
Code
Copy-paste the following code to your user application:
Workflow
- Enter an infinite loop while the timer is running.