TM4C1294NCPDT Datasheet, PDF (549/1890 Pages) Texas Instruments – Tiva Microcontroller

Tiva^™ TM4C1294NCPDT Microcontroller
7.4.2
7.4.3
If a 32.768-kHz single-ended oscillator is used as the Hibernation module clock source, then perform
the following steps:
1. Write 0x0000.0010 to the HIBIM register to enable the WC interrupt.
2. Write 0x0001.0040 to the HIBCTL register at offset 0x10 to enable the oscillator input and
bypass the on-chip oscillator.
3. Wait until the WC interrupt in the HIBMIS register has been triggered before performing any other
operations with the Hibernation module.
If the internal low frequency oscillator is used as the Hibernation module clock source, then perform
the following steps:
1. Write 0x0000.0010 to the HIBIM register to enable the WC interrupt.
2. Write 0x0008.0040 to the HIBCTL register at offset 0x10 to enable the internal low frequency
oscillator.
3. Wait until the WC interrupt in the HIBMIS register has been triggered before performing any other
operations with the Hibernation module.
The above steps are only necessary when the entire system is initialized for the first time. If the
microcontroller has been in hibernation, then the Hibernation module has already been powered
up and the above steps are not necessary. The software can detect that the Hibernation module
and clock are already powered by examining the CLK32EN bit of the HIBCTL register.
RTC Match Functionality (No Hibernation)
Use the following steps to implement the RTC match functionality of the Hibernation module:
1. Write 0x0000.0040 to the HIBCTL register at offset 0x010 to enable 32.768-kHz Hibernation
oscillator.
2. Write the required RTC match value to the HIBRTCM0 register at offset 0x004 and the RTCSSM
field in the HIBRTCSS register at offset 0x028.
3. Write the required RTC load value to the HIBRTCLD register at offset 0x00C.
4. Set the required RTC match interrupt mask in the RTCALT0 in the HIBIM register at offset 0x014.
5. Write 0x0000.0041 to the HIBCTL register at offset 0x010 to enable the RTC to begin counting.
RTC Match/Wake-Up from Hibernation
Use the following steps to implement the RTC match and wake-up functionality of the Hibernation
module:
1. Write 0x0000.0040 to the HIBCTL register at offset 0x010 to enable 32.768-kHz Hibernation
oscillator.
2. Write the required RTC match value to the HIBRTCM0 register at offset 0x004 and the RTCSSM
field in the HIBRTCSS register at offset 0x028.
3. Write the required RTC load value to the HIBRTCLD register at offset 0x00C. This write causes
the 15-bit sub seconds counter to be cleared.
June 18, 2014
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