1.6 Clock Configuration
This example application shows how to configure the clock system to run the device at maximum frequency. It also outputs a prescaled clock signal on a GPIO pin for measurement and verification.
Description
Clock system generates and distributes the clock for the processor and peripherals. This example application shows how to use the clock manager to configure the device to run at the max possible speed. A prescaled clock signal is routed to GPIO pin to measure the frequency and accuracy of the internal device clock.
Downloading and Building the Application
To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file. This content can also be downloaded using content manager by following these instructions.
Path of the application within the repository is apps/clock/clock_config/firmware.
To build the application, refer to the following table and open the project using its IDE.
| Project Name | Description |
|---|---|
| sam_e70_xult.X | MPLABX project for SAM E70 Xplained Ultra Evaluation Kit |
| sam_v71_xult.X | MPLABX project for SAM V71 Xplained Ultra Evaluation Kit |
Setting Up the Hardware
The following table shows the target hardware for the application projects.
| Project Name | Description |
|---|---|
| sam_e70_xult.X | SAM E70 Xplained Ultra Evaluation Kit |
| sam_v71_xult.X | SAM V71 Xplained Ultra Evaluation Kit |
Setting Up SAM E70 Xplained Ultra Evaluation Kit
- Connect an oscilloscope to monitor the PORT pin PA03 (J505 header on the SAM E70 Xplained Ultra Evaluation Kit)
- Connect the Debug USB port on the board to the computer using a micro USB cable
Setting Up SAM V71 Xplained Ultra Evaluation Kit
- Connect an oscilloscope to monitor the PORT pin PA03 (Pin 11 of EXT1 header on the SAM V71 Xplained Ultra Evaluation Kit)
- Connect the Debug USB port on the board to the computer using a micro USB cable
Running the Application
- Build and Program the application using its IDE
- Observe a clock of 5 MHz on the clock output pin
- LED should be blinking continuously
| Board | Clock Output Pin | LED Name |
|---|---|---|
| SAM E70 Xplained Ultra Evaluation Kit | PA03 (J505 header) | LED1 |
| SAM V71 Xplained Ultra Evaluation Kit | PA03 (Pin 11 on the EXT1 header) | LED0 |