CC2652R7: Configuring peripherals for low power consumption

Part Number: CC2652R7

Tool/software:

Hello,

I'm working on an application with version 5.10.00.48 of the simplelink SDK, running on a custom board that requires power consumption to be as low as possible. The application is based on the simple_peripheral example project, hence it uses pretty much the same power management configuration, including allowing transitions into Standby power mode. As part of this task, I'm trying to disable any peripherals while not in use through the TI RTOS drivers functions e.g. SPI_close. When doing so, I notice that the clock gate registers related to the peripheral being closed (e.g. SSICLKGR, SSICLKGS, SSICLKGDS) are updated to disable the peripheral's clock in the different power modes. However, I don't notice any change in power consumption. If I'm interpreting the microcontroller data sheet correctly, the current consumption of e.g. SSI module with clock enabled in idle mode should be 61uA. When disabling this and other module's clocks, should I expect a reduction in current consumption around the values specified in the data sheet? Is there any other indicator of a peripheral's state besides the clock gate registers?


Thanks,

Julian

  • Hi,

    If you are using the launchpad the debug circuitry, SPI external flash, LEDS on and UART open will add to current consumption. At initialization SPI will be closed so you do not need to worry about that.

    -kel

  • Hello Julian,

    Thanks for reaching out. If you have a CC26xx LaunchPad you could try to use EngeryTrace++ which allows more detailed data regarding power consumption (see EnergyTrace++ Instructions).

    BR,

    David.

  • Some additional info. I'm using IAR 8.50.9. The application is custom and it consists of two microcontrollers, custom ASIC and other components. The two microcontrollers are CC2652R7 and MSP430. The MSP430 firmware is known to be setting this microcontroller and custom ASIC to the lowest power, so we’re currently working on the CC2652R7 firmware to try to reduce its current draw as much as possible.

    More specifically in the CC2652R7 application, it is based on the simple_peripheral example project, and it acts as an interface between external devices and the MSP430 and custom ASIC. We’re trying to see if configuring some of its internal peripherals so that their clocks are disabled when not in use could result in further power savings. I was trying to do so by using the "close" function for some of the drivers (e.g. SPI_close) but I don’t see any change in current consumption when doing so. We’re also trying to investigate what would be the best way to disable the Crypto and PKA peripherals when not in use.

  • Hi Julian,

    I have worked with similar hardware setup. Your additional circuitry connected to CC2652R7 adds to current consumption. So, it's difficult to know if doing this and that contributed to additional current consumption. What you can do is study the launchpad current consumption. As I have mentioned above those are what will add to current consumption. Also you would need appropriate testing tools to measure current consumption such as DC power analyzer. After finding out the appropriate setting to achieve low power consumption using the launchpad, then you can implement the same to your custom hardware.

    -kel