PSoC™ 6 MCU: Switching between power modes

This example demonstrates how to transition PSoC™ 6 MCU to the following system and MCU power states:

• System power states - Normal power state/low-power state
• MCU power states - Active/sleep/deep sleep

View this README on GitHub.

Provide feedback on this code example.

Overview

This code example shows how to enter system normal and low-power states, and transition to MCU active, sleep, or deep sleep power states. The system power states affect the whole device, while the MCU power states affect only one CPU. After transitioning to deep sleep or sleep power state, the example also shows how to wake up and return to Normal or Low Power state.

This example does not cover hibernate mode. For more information on this mode, see the PSoC™ 6 MCU documentation. AN219528 - PSoC™ 6 MCU low-power modes and power reduction techniques provides additional details on the PSoC™ 6 MCU power modes, use of the SysPM driver, and other recommendations for reducing power consumption. Some nomenclature between the CYHAL driver and the PSoC™ 6 PDL are different as follows:

Table 1. Power management nomenclature differences

CYHAL driver	PSoC™ 6 PDL
Normal state	Low-power mode
Low-power state	Ultra-low-power mode
MCU active	CPU active
MCU sleep	CPU sleep

The project uses a kit button to change the power state. Figure 1 shows the state machine implemented in the firmware to execute the transitions.

Figure 1. Power state machine

The project also uses one LED to indicate the selected power state. Table 2 shows the state of the LED for each mode.

Table 2. LED states in various power states

Power/MCU states	LED state
Normal power/MCU active	Blinks rapidly
Normal power/MCU sleep	Turned ON and bright
Low-power/MCU active	Blinks slowly
Low-power/MCU sleep	Turned ON and dimmed
Deep sleep	Turned OFF

Requirements

• ModusToolbox™ software v3.0 or later (tested with v3.0)
• Board support package (BSP) minimum required version: 4.0.0
• Programming language: C
• Associated parts: All PSoC™ 6 MCU parts

Supported toolchains (make variable 'TOOLCHAIN')

• GNU Arm® embedded compiler v10.3.1 (GCC_ARM) - Default value of TOOLCHAIN
• Arm® compiler v6.16 (ARM)
• IAR C/C++ compiler v9.30.1 (IAR)

Supported kits (make variable 'TARGET')

• PSoC™ 6 Wi-Fi Bluetooth® prototyping kit (CY8CPROTO-062-4343W) - Default value of TARGET
• PSoC™ 6 Wi-Fi Bluetooth® pioneer kit (CY8CKIT-062-WIFI-BT)
• PSoC™ 6 Bluetooth® LE pioneer kit (CY8CKIT-062-BLE)
• PSoC™ 6 Bluetooth® LE prototyping kit (CY8CPROTO-063-BLE)
• PSoC™ 62S1 Wi-Fi Bluetooth® pioneer kit (CYW9P62S1-43438EVB-01)
• PSoC™ 62S1 Wi-Fi Bluetooth® pioneer kit (CYW9P62S1-43012EVB-01)
• PSoC™ 62S2 Wi-Fi Bluetooth® pioneer kit (CY8CKIT-062S2-43012)
• PSoC™ 62S2 evaluation kit (CY8CEVAL-062S2, CY8CEVAL-062S2-LAI-4373M2)
• PSoC™ 62S3 Wi-Fi Bluetooth® prototyping kit (CY8CPROTO-062S3-4343W)
• PSoC™ 62S4 pioneer kit (CY8CKIT-062S4)
• PSoC™ 64 "Secure Boot" Wi-Fi Bluetooth® pioneer kit (CY8CKIT-064B0S2-4343W)
• Rapid IoT connect developer kit (CYSBSYSKIT-DEV-01)

Hardware setup

This example uses the board's default configuration. See the kit user guide to ensure that the board is configured correctly.

The example does not require any additional hardware to run. However, you can connect an ammeter to measure the current consumed by the PSoC™ MCU device. If using any of the PSoC™ 6 MCU pioneer kits, remove the PWR_MON jumper from the kit and connect the ammeter on the header pins. This jumper is at the bottom side of the PSoC™ 6 MCU pioneer kits. See the kit guide for the exact location. If using a prototyping board kit, see the kit guide how to measure the current. It might require changes in the hardware.

Note: The PSoC™ 6 Bluetooth® LE pioneer kit (CY8CKIT-062-BLE) and the PSoC™ 6 Wi-Fi Bluetooth® pioneer kit (CY8CKIT-062-WIFI-BT) ship with KitProg2 installed. The ModusToolbox™ software requires KitProg3. Before using this code example, make sure that the board is upgraded to KitProg3. The tool and instructions are available in the Firmware Loader GitHub repository. If you do not upgrade, you will see an error like "unable to find CMSIS-DAP device" or "KitProg firmware is out of date".

Software setup

This example requires no additional software or tools.

Using the code example

Create the project and open it using one of the following:

In Eclipse IDE for ModusToolbox™ software

1. Click the New Application link in the Quick Panel (or, use File > New > ModusToolbox Application). This launches the Project Creator tool.

2. Pick a kit supported by the code example from the list shown in the Project Creator - Choose Board Support Package (BSP) dialog.

   When you select a supported kit, the example is reconfigured automatically to work with the kit. To work with a different supported kit later, use the Library Manager to choose the BSP for the supported kit. You can use the Library Manager to select or update the BSP and firmware libraries used in this application. To access the Library Manager, click the link from the Quick Panel.

   You can also just start the application creation process again and select a different kit.

   If you want to use the application for a kit not listed here, you may need to update the source files. If the kit does not have the required resources, the application may not work.

3. In the Project Creator - Select Application dialog, choose the example by enabling the checkbox.

4. (Optional) Change the suggested New Application Name.

5. The Application(s) Root Path defaults to the Eclipse workspace which is usually the desired location for the application. If you want to store the application in a different location, you can change the Application(s) Root Path value. Applications that share libraries should be in the same root path.

6. Click Create to complete the application creation process.

For more details, see the Eclipse IDE for ModusToolbox™ software user guide (locally available at {ModusToolbox™ software install directory}/ide_{version}/docs/mt_ide_user_guide.pdf).

In command-line interface (CLI)

ModusToolbox™ software provides the Project Creator as both a GUI tool and the command line tool, "project-creator-cli". The CLI tool can be used to create applications from a CLI terminal or from within batch files or shell scripts. This tool is available in the {ModusToolbox™ software install directory}/tools_{version}/project-creator/ directory.

Use a CLI terminal to invoke the "project-creator-cli" tool. On Windows, use the command line "modus-shell" program provided in the ModusToolbox™ software installation instead of a standard Windows command-line application. This shell provides access to all ModusToolbox™ software tools. You can access it by typing modus-shell in the search box in the Windows menu. In Linux and macOS, you can use any terminal application.

The "project-creator-cli" tool has the following arguments:

Argument	Description	Required/optional
--board-id	Defined in the <id> field of the BSP manifest	Required
--app-id	Defined in the <id> field of the CE manifest	Required
--target-dir	Specify the directory in which the application is to be created if you prefer not to use the default current working directory	Optional
--user-app-name	Specify the name of the application if you prefer to have a name other than the example's default name	Optional

The following example will clone the "Hello World" application with the desired name "MyHelloWorld" configured for the CY8CKIT-062-WIFI-BT BSP into the specified working directory, C:/mtb_projects:

project-creator-cli --board-id CY8CKIT-062-WIFI-BT --app-id mtb-example-psoc6-hello-world --user-app-name MyHelloWorld --target-dir "C:/mtb_projects"

Note: The project-creator-cli tool uses the git clone and make getlibs commands to fetch the repository and import the required libraries. For details, see the "Project creator tools" section of the ModusToolbox™ software user guide (locally available at {ModusToolbox™ software install directory}/docs_{version}/mtb_user_guide.pdf).

To work with a different supported kit later, use the Library Manager to choose the BSP for the supported kit. You can invoke the Library Manager GUI tool from the terminal using make library-manager command or use the Library Manager CLI tool "library-manager-cli" to change the BSP.

The "library-manager-cli" tool has the following arguments:

Argument	Description	Required/optional
--add-bsp-name	Name of the BSP that should be added to the application	Required
--set-active-bsp	Name of the BSP that should be as active BSP for the application	Required
--add-bsp-version	Specify the version of the BSP that should be added to the application if you do not wish to use the latest from manifest	Optional
--add-bsp-location	Specify the location of the BSP (local/shared) if you prefer to add the BSP in a shared path	Optional

Following example adds the CY8CPROTO-062-4343W BSP to the already created application and makes it the active BSP for the app:

library-manager-cli --project "C:/mtb_projects/MyHelloWorld" --add-bsp-name CY8CPROTO-062-4343W --add-bsp-version "latest-v4.X" --add-bsp-location "local"

library-manager-cli --project "C:/mtb_projects/MyHelloWorld" --set-active-bsp APP_CY8CPROTO-062-4343W

In third-party IDEs

Use one of the following options:

• Use the standalone Project Creator tool:

  1. Launch Project Creator from the Windows Start menu or from {ModusToolbox™ software install directory}/tools_{version}/project-creator/project-creator.exe.

  2. In the initial Choose Board Support Package screen, select the BSP, and click Next.

  3. In the Select Application screen, select the appropriate IDE from the Target IDE drop-down menu.

  4. Click Create and follow the instructions printed in the bottom pane to import or open the exported project in the respective IDE.

• Use command-line interface (CLI):

  1. Follow the instructions from the In command-line interface (CLI) section to create the application.

  2. Export the application to a supported IDE using the make <ide> command.

  3. Follow the instructions displayed in the terminal to create or import the application as an IDE project.

For a list of supported IDEs and more details, see the "Exporting to IDEs" section of the ModusToolbox™ software user guide (locally available at {ModusToolbox™ software install directory}/docs_{version}/mtb_user_guide.pdf).

Operation

If using a PSoC™ 64 "Secure" MCU kit (like CY8CKIT-064B0S2-4343W), the PSoC™ 64 device must be provisioned with keys and policies before being programmed. Follow the instructions in the "Secure Boot" SDK user guide to provision the device. If the kit is already provisioned, copy-paste the keys and policy folder to the application folder.

1. Program the board using one of the following:

   Using Eclipse IDE for ModusToolbox™ software

   1. Select the application project in the Project Explorer.

   2. In the Quick Panel, scroll down, and click <Application Name> Program (KitProg3_MiniProg4).

   Using CLI

   From the terminal, execute the make program command to build and program the application using the default toolchain to the default target. The default toolchain is specified in the application's Makefile but you can override this value manually:

   make program TOOLCHAIN=<toolchain>
   

   Example:

   make program TOOLCHAIN=GCC_ARM
   

2. After programming, the application starts automatically. Confirm that kit LED blinks at 5 Hz (approximately). Take note of the current consumption. The device is in the normal power/MCU active state at this moment.

3. Press the kit button for approximately one second and release it. Observe that the LED is ON and fully bright. Confirm that the current consumption drops a few hundreds of microamperes. The device is in the normal power/MCU sleep state at this moment.

4. Quickly press the kit button to return to Normal power/MCU active state. Observe that the LED blinks quickly again.

5. Press the kit button for at least two seconds and release it. Observe that the LED is OFF and that the current consumption has dropped to a few microamperes. The device is in deep sleep state at this moment.

6. Quickly press the kit button to return to normal power state. Observe that the LED blinks quickly and that the current consumption has increased to the same level measured before.

7. Quickly press the kit button again to enter low-power state. Observe that the LED blinks slowly and that the current consumption has dropped significantly when compared to normal power state. You can quickly press the kit button to switch between the two modes.

8. Keep the device in low-power state and press the kit button for approximately one second and release it. Observe that the LED dims and that the current consumption has dropped a few hundred microamperes. The device is in the low-power/MCU sleep state at this moment.

9. Quickly press the kit button to return to the low-power/MCU active state. Observe that the is blinking slowly again.

10. Press the kit button for at least two seconds and release it. Observe that the LED is OFF and that the current consumption has dropped to a few microamperes. The device is in deep sleep state at this moment.

11. Quickly press the user button and return to the low-power/MCU active state. Observe that the LED blinks slowly again and that the current consumption has increased to the same level measured before.

Debugging

You can debug the example to step through the code. In the IDE, use the <Application Name> Debug (KitProg3_MiniProg4) configuration in the Quick Panel. For more details, see the "Program and debug" section in the Eclipse IDE for ModusToolbox™ software user guide.

Note: (Only while debugging) On the CM4 CPU, some code in main() may execute before the debugger halts at the beginning of main(). This means that some code executes twice - once before the debugger stops execution, and again after the debugger resets the program counter to the beginning of main(). See KBA231071 to learn about this and for the workaround.

Design and implementation

This example configures the a PWM to blink, dim, and turn ON/OFF the LED. The firmware implements the state machine shown in the Overview section and controls the duty cycle of the PWM block. The device wakes up when a switch press is detected.

Figure 2. Flowchart

Two power management callback functions are registered (PWM and Clock callbacks). Table 3 shows the actions of each callback function for every power state. For more information on power callbacks, see the CYHAL driver - system power management.

Table 3. Transition actions

Callback	Power state	CHECK_READY	CHECK_FAIL	BEFORE_TRANSITION	AFTER_TRANSITION
PWM callback	Sleep	Nothing	Nothing	If in low-power state, dim the LED. If in normal power state, turn ON the LED.	If in low -power state, blink the LED slowly. If in normal power state, blink the LED fast.
PWM callback	Deep sleep	Nothing	Nothing	Stop PWM	Re-enable the PWM block. If in low-power state, blink the LED slowly. If in normal power state, blink the LED fast.
PWM callback	Low-power	Nothing	Nothing	Nothing	Blink the LED slowly.
PWM callback	Normal power	Nothing	Nothing	Nothing	Blink the LED fast
Clock callback	Low-power	Nothing	Nothing	Reconfigure the System Clock to 50 MHz.	Nothing
Clock callback	Normal power	Nothing	Nothing	Nothing	Reconfigure the System Clock to 100 MHz

Resources and settings

Table 4. Application resources

Resource	Alias/object	Purpose
PWM (HAL)	pwm	Used to control the LED brightness
Clock (HAL)	system_clock	Used to configure the system clock
GPIO (HAL)	CYBSP_USER_BTN	Used to wake up the device and change power states

Related resources

Resources	Links
Application notes	AN228571 – Getting started with PSoC™ 6 MCU on ModusToolbox™ software AN215656 – PSoC™ 6 MCU: Dual-CPU system design AN79953 – Getting started with PSoC™ 4 AN85951 – PSoC™ 4 and PSoC™ 6 MCU CAPSENSE™ design guide
Code examples	Using ModusToolbox™ software on GitHub Using PSoC™ Creator
Device documentation	PSoC™ 6 MCU datasheets PSoC™ 6 technical reference manuals PSoC™ 4 datasheets PSoC™ 4 technical reference manuals
Development kits	Visit www.cypress.com/microcontrollers-mcus-kits and use the options in the Select your kit section to filter kits by Product family or Features.
Libraries on GitHub	mtb-pdl-cat1 – PSoC™ 6 peripheral driver library (PDL) mtb-hal-cat1 – Hardware abstraction layer (HAL) library retarget-io – Utility library to retarget STDIO messages to a UART port
Middleware on GitHub	capsense – CAPSENSE™ library and documents psoc6-middleware – Links to all PSoC™ 6 MCU middleware
Tools	Eclipse IDE for ModusToolbox™ software – ModusToolbox™ software is a collection of easy-to-use software and tools enabling rapid development with Infineon MCUs, covering applications from embedded sense and control to wireless and cloud-connected systems using AIROC™ Wi-Fi and Bluetooth® connectivity devices.

Other resources

Infineon provides a wealth of data at www.infineon.com to help you select the right device, and quickly and effectively integrate it into your design.

For PSoC™ 6 MCU devices, see How to design with PSoC™ 6 MCU - KBA223067 in the Infineon Developer community.

Document history

Document title: CE219881 - PSoC™ 6 MCU: Switching between power modes

Version	Description of change
1.0.0	New code example
1.1.0	Updated to support ModusToolbox™ software v2.1 Updated to use HAL drivers for power management
2.0.0	Major update to support ModusToolbox™ software v2.2, added support for new kits This version is not backward compatible with ModusToolbox™ software v2.1
2.1.0	Added support for CYSBSYSKIT-DEV-01 Rapid IoT Connect Developer Kit
2.2.0	Updated to support ModusToolbox™ software v2.3 Added support for new kits
3.0.0	Major update to support ModusToolbox™ v3.0 and BSPs v4.X. This version is not backward compatible with previous versions of ModusToolbox
3.1.0	Fixed incorrect low power to active power switching sequence

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