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.
7.4.2
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.
7.4.3
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.
549
June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C1294NCPDT Microcontroller