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Come back from RTC mode

Sergey Zevelev
Prodigy 90 points

Hi

My device is consumed about 60 mA. DSP(5504) is clocked by internal RTC oscillator and the internal PLL generates 100 MHz system clock.  VDDA_PLL is powered by ANA_LDO (1.3V). When I have written LDO_PD=1 into RTCPGMT register (using CCS4),  ANA_LDO voltage drop till 0.3 V, device current consumption is drops from 60 till 18 mA and RTC oscillator is working.

So, DSP is came into RTC mode only. 

After I have asserted "High" on the DSP WAKEUP pin, but it  is not occurred nothing.  ANA_LDO voltage is not came back to 1.3V, DSP is left in RTC mode and total current consumption is not enlarged.  

How DSP may be came back into the normal mode?

 

Thanks

Sergey

  • 0
    TI__Mastermind 30110 points

    Hi Sergey,

    The details are described in the C5504 datasheet - http://www.ti.com/lit/ds/symlink/tms320c5504.pdf

    See 6.11.1 RTC Only Mode

    Are you following the procedure?

    What is the voltage of the CVDD supply during the wakeup pulse? The C5504 does not have the DSP LDO, so CVDD must be suppied externally, and voltage applied during the wakeup pulse.

    Regards,
    Mark

  • 0 in reply to Mark M
    Prodigy 90 points

    Hi Mark

    It is not clear what is CVDD, if voltage core, it is connected constantly to 1.3V  (pins F6, H8, J6, K10,L5) . What, is core pins must be unpowered during RTC only mode? Other pins:

    ·         Pin F14 DSP_LDO_IN  connected to 3.3V

    ·         Pin B12 ANA_LDOI  connected to 3.3V

    ·         Pin E10 DSP_LDO  not connected

    ·         Pin D13 DSP_LDO_V pulled up by 10 k to 3.3V

    ·         Pin D12 DSP_LDO_EN  pulled down by 20k.

    ·         Pin C8 RTC_VDD connected to 1.3V

    ·         Pin F8 DV_DRTC – connected to 3.3V

    ·         Pin C10 VDDA_PLL connected to pin A12 ANA_LDO.

    According to my opinion, all pins are connected according to data sheet.

    Best regards

    Sergey

  • 0 in reply to Sergey Zevelev
    Prodigy 90 points

    Dear Mr.Ms

     

    Full week is over, but you did not answer for my question. Why DSP does not come back to normal mode from RTC only mode by asserting HIGH on WAKEUP pin? In previous my letter I have listed all power voltages values on the specific DSP pins. Please replay me as soon as possible.

    Best regards

     

    Sergey