Texas Instruments TM4C1294NCPDT User Manual

6. The hibernation sequence may be initiated by writing 0x4000.0152 to the HIBCTL register. Note
for Port M external wake, the user must enable VDD3ON mode and set the RETCLR bit in the
HIBCTL register.
7.4.5 RTC or External Wake-Up from Hibernation
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.
4. Write any data to be retained during hibernation to the HIBDATA register at offsets 0x030-0x06F.
5. Set the RTC Match/External Wake-Up and start the hibernation sequence by writing 0x0000.005B
to the HIBCTL register at offset 0x010.
7.4.6 Tamper Initialization
Use the following steps to configure the Tamper module to interrupt the processor when a TMPR
signal has triggered:
Note: Unlike other functions, the Tamper pins do not need to be configured for the GPIO in the
GPIOAFSEL register. The Tamper IO Control and Status (HIBTPIO) register overrides
configurations made to the GPIO module.
1. Write 0x0000.0041 to the HIBCTL register at offset 0x010 to enable the 32.768-kHz Hibernate
oscillator and enable the RTC.
2. Enable the four Tamper I/O to trigger on the a high state on any of the pins by writing
0x0F0F.0F0F to the HIBTPIO register at offset 0x410.
3. Write 0x0000.0001 to the HIBTPCTL register to enable the tamper.
Note: Once tamper is enabled, the following HIBCTL register bits are locked and cannot be
modified:
■ OSCSEL
■ OSCDRV
■ OSCBYP
■ VDD3ON
■ CLK32EN
■ RTCEN
7.5 Register Map
Table 7-3 on page 552 lists the Hibernation registers. All addresses given are relative to the Hibernation
Module base address at 0x400F.C000. Note that the system clock to the Hibernation module must
be enabled before the registers can be programmed (see page 387). There must be a delay of 3
system clocks after the Hibernation module clock is enabled before any Hibernation module registers
551June 18, 2014
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TM4C1294NCPDT Microcontroller

Texas Instruments TM4C1294NCPDT Specifications

General

Brand	Texas Instruments
Model	TM4C1294NCPDT
Category	Microcontrollers
Language	English