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Getting VPLL1 to turn OFF with nSLEEP1

Other Parts Discussed in Thread: TPS65950, OMAP3530

I have SYS_OFF_MODE from the OMAP3530 connected to the nSLEEP1 signal on the TPS65950, and I can see the nSLEEP1 signal going low.  However, the VPLL1 voltage stays at 1.8V, even though I think I have configured the TPS65950 to turn it off when nSLEEP1 goes low.  I have...

  1. Created a sleep script that I think should tell VPLL1 to go to sleep.
    1. BroadcastMsg DEV_GRP_NULL,  RES_GRP_ALL, Type=2, Type2=1, STATE=Sleep, delay 2, next address 0x2c
    2. BroadcastMsg DEV_GRP_NULL,  RES_GRP_ALL, Type=1, Type2=1, STATE=Sleep, delay 2, next address 0x2d
    3. SingleMsg DEV_GRP_NULL, 0x7 (VPLL1), STATE=Off, delay 2, next address 0x3f
  2. Loaded that script into script memory at address 0x2b
  3. Set the SEQ_ADD_A2S to 0x2b
  4. Set VPLL1_DEV_GRP to 0x2e (belongs to resource group P1)
  5. Set VPLL1_TYPE to 0x0a (TYPE2 = 1, TYPE = 2)
  6. Set VPLL1_REMAP to 0 (sleep and off both map to the OFF state)
  7. Set P1_SW_EVENTS to 0x18 to enable nSLEEP1 to control P1 grouped resources

I have attempted to attach a log of the I2C bus communications for your perusal--hopefully it will work.  4113.I2C1-TPS65950-Traffic.xlsx

Does nSLEEP1 directly control the P1 resources or does it invoke the sleep script for the P1 resources when it falls?

What am I missing?

 

Thanks,

 

Chris

  • I just read again this note in the TRM:

    NOTE: If an AC charger is plugged in, T2 cannot go into SLEEP state and thus does not execute
    the ACTIVE-to-SLEEP sequence, even if nSLEEP1, nSLEEP2, and CLKREQ are low.

    I am doing this test on the Mistral EVM powered by a 5V power supply, which I learned after some investigation, by default acts like it has an AC charger plugged in.  By disabling the AC charger and jumpering VBAT to VBAT_IN, it now drops VPPL1 when nSLEEP1 goes low.

  • Thanks for sharing your observation.