RE: High Current Draw With Floating Point Calculation

Marten — Mon, 24 Sep 2018 15:15:04 GMT

Just saw that the fix is also used when calling nrf_pwr_mgmt_run() (in nrf_pwr_mgmt.c)

__STATIC_INLINE void pwr_mgmt_fpu_sleep_prepare(void)
{
    uint32_t fpscr;
    CRITICAL_REGION_ENTER();
    fpscr = __get_FPSCR();
    /*
    * Clear FPU exceptions.
    * Without this step, the FPU interrupt is marked as pending,
    * preventing system from sleeping. Exceptions cleared:
    * - IOC - Invalid Operation cumulative exception bit.
    * - DZC - Division by Zero cumulative exception bit.
    * - OFC - Overflow cumulative exception bit.
    * - UFC - Underflow cumulative exception bit.
    * - IXC - Inexact cumulative exception bit.
    * - IDC - Input Denormal cumulative exception bit.
    */
    __set_FPSCR(fpscr & ~0x9Fu);
    __DMB();
    NVIC_ClearPendingIRQ(FPU_IRQn);
    CRITICAL_REGION_EXIT();

    /*
    * Assert no critical FPU exception is signaled:
    * - IOC - Invalid Operation cumulative exception bit.
    * - DZC - Division by Zero cumulative exception bit.
    * - OFC - Overflow cumulative exception bit.
    */
    ASSERT((fpscr & 0x07) == 0);
}

RE: High Current Draw With Floating Point Calculation

Ken — Mon, 17 Jul 2017 19:35:58 GMT

That fixed the issue. Thank-you ken

RE: High Current Draw With Floating Point Calculation

Jørgen Holmefjord — Mon, 17 Jul 2017 15:04:18 GMT

Hi,

Make sure you have implemented the workaround for PAN-87 - CPU: Unexpected wake from System ON Idle when using FPU.

Best regards,

Jørgen