TM4C1231H6PM: Hibernate TRIM Register.. TM4C1231H6PM & TM4C1291

Hi Merril,

Newman said:

In The Hibernate example for the TM4C123_evk the following lines of code are present.

I didn’t see this noted in any Errata I read so am wondering if it should still be done (and if yes, what parts revs are affected) ?

The comment in the code is referring to HIB#01. See below conditions under which the errata can occur. HIBRTCT is the trim register which is mentioned as one of the affected registers. 

Newman said:

//

    // Re-intializes the Trim which gets modified due to a known issue of

    // Hibernate register initialization from HIB#01 errata.

    //

    MAP_HibernateRTCTrimSet(0x7FFF);

The default value of the trim register is 0x7FFF. However, due to the errata, the content of the register may not be correct. To work around the errata, the call of HibernateRTCTrimSet(0x7FFF) makes sure that the trim register has the correct value after RTC is enabled. 

Newman said:

Does this happen on the TM4C129 parts too ?

No, this does not affect TM4C129. The errata mentioned for TM4C123 is not shown in the TM4C129 errata document and neither the workaround is shown in the TM4C129 hibernate example.