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MSP430FR2311: LPM3 current consumption for simplest code ever is too high

kazola
Guru 18625 points

Part Number: MSP430FR2311
Other Parts Discussed in Thread: ENERGYTRACE, , MSP430G2553

Dear,

just switched to msp430fr2311 so probably I am omitting something. Energytrace indicates a consumption of tens of uA when running the following code:

#include <msp430.h>


// conf GPIO for low-power consumption
void initGpio(void)
{
    P1DIR = 0xFF; P2DIR = 0xFF;
    P1REN = 0xFF; P2REN = 0xFF;
    P1OUT = 0x00; P2OUT = 0x00;

    // switch from GPIO default boot high-Z to the settings above
    PM5CTL0 &= ~LOCKLPM5;
}



void main(void)
{
    // stop watchdog
    WDTCTL = WDTPW | WDTHOLD;


    // conf GPIO for low-power
    initGpio();


    __bis_SR_register(LPM3_bits);

}

I am just being curious. I tried some of the samples for LPM3.5 and the consumption is ok.

So, what am I omitting in such simple code above? I have always used this for msp430g2553 with complete success :)

Oh, by the way, the jumpers for the light sensor circuit in the launchpad, as well as for the debugging interface, are removed.

Have a really nice day! Let me know your opinion!

  • 0
    TI__Genius 13215 points
    Hi Kazola,

    If you use the FR2311 launchpad, it have no crystal assembled on the board as default.

    So as your code shows, the REFO should be ON when the device goes into LPM3. The REFO oscillator current consumption should be about 15uA with typical (See the data in table5-7 of the device datasheet).

    If you want to get the power consumption of the LPM3 shown in the table of section5.7 of the datasheet, you should assemble a crystal circuit and configure your board as the note 2,3,4/5/6 shown below the table of section5.7.

    Wei,
    MSP430 Customer Apps.
  • 0 in reply to Wei.Jetim Zhao
    Guru 18625 points

    Dear ,

    thanks for you answer! That was useful :)

    However, I do not plan to deploy a crystal with my current project. So, can I simply switch off REFO?

  • 0 in reply to kazola
    TI__Genius 13215 points

    Hi Kazola,

    You can't turn off the REFO without a LF crystal operating properly in LPM3.

    If you still want to switch off the REFO, please select LPM4 or LPMx.5 following the Table 6-1 for Operation Modes  of the Device Datasheet.

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