TM4C123GH6PGE Datasheet, PDF (514/1467 Pages) Texas Instruments – Tiva Microcontroller

Hibernation Module
Figure 7-5. Counter Behavior with a TRIM Value of 0x8002
RTCCLK
RTCC[6:0]
0x00
0x01
0x02
RTCSSC 0x7FFD 0x7FFE 0x7FFF 0x7FFD 0x7FFE 0x7FFF 0x0 0x7FFE 0x7FFF 0x0 0x1
In the case of a trim value below 0x7FFF, the RTCSSC value is advanced from 0x7FFF to the trim
value while the RTCC value is incremented from 0x0 to 0x1. If the match value is within that range,
the match interrupt is not triggered. For example, as shown in Figure 7-6 on page 514, if the match
interrupt was configured with RTCM0=0x1 and RTCSSM=0x2,an interrupt would never be triggered.
Figure 7-6. Counter Behavior with a TRIM Value of 0x7FFC
RTCCLK
RTCC[6:0]
0x00
0x01
RTCSSC 0x7FFD 0x7FFE 0x7FFF 0x7FFD 0x7FFE 0x7FFF
7.3.6
7.3.7
Battery-Backed Memory
The Hibernation module contains 16 32-bit words of memory that are powered from the battery or
an auxiliary power supply and therefore retained during hibernation. The processor software can
save state information in this memory prior to hibernation and recover the state upon waking. The
battery-backed memory can be accessed through the HIBDATA registers. If both V_DD and V_BAT are
removed, the contents of the HIBDATA registers are not retained.
Power Control Using HIB
Important: The Hibernation Module requires special system implementation considerations when
using HIB to control power, as it is intended to power-down all other sections of the
microcontroller. All system signals and power supplies that connect to the chip must
be driven to 0 V or powered down with the same regulator controlled by HIB.
The Hibernation module controls power to the microcontroller through the use of the HIB pin which
is intended to be connected to the enable signal of the external regulator(s) providing 3.3 V to the
microcontroller and other circuits. When the HIB signal is asserted by the Hibernation module, the
external regulator is turned off and no longer powers the microcontroller and any parts of the system
that are powered by the regulator. The Hibernation module remains powered from the V_BAT supply
until a Wake event. Power to the microcontroller is restored by deasserting the HIB signal, which
causes the external regulator to turn power back on to the chip.
514
June 12, 2014
Texas Instruments-Production Data