TPS65311-Q1: LOCKED state difinition

Hi Oguri,

   The device expert is still on vacation. Copied below from P.24 of the datasheet has better explanation about it.  

   Any reset event (without POR, thermal shutdown, or loss of LPM clock) increments the error counter (EC) by one. After a reset is consecutively triggered NRES times, the device transfers to the LPM0 state, and the EC is reset to 0. The counter is decremented by one if an SPI LPM0_CMD is received. Alternatively, the device can be put in LOCK state once an SPI LOCK_CMD is received. Once the device is locked, it cannot be activated again by a wake condition. The reset counter and lock function avoid cyclic start-up and shut-down of the device in case of a persistent fault condition. The reset counter content is cleared with a POR condition, a thermal shutdown or a loss of LPM clock. Once the device is locked, a voltage below VPOR at VIN pin or a thermal shutdown condition are the only ways to unlock the device.

  Please let's know if you still have further questions. 

Thanks!

Phil