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RTCCLK
RTCC[6:0]
RTCSSC
0x00
0x7FFD
0x7FFE
0x01
0x7FFF
0x7FFD
0x7FFE
0x7FFF
RTCCLK
RTCC[6:0]
RTCSSC
0x00
0x7FFD
0x7FFE
0x01
0x02
0x7FFF
0x7FFD 0x7FFE
0x7FFF
0x7FFE
0x7FFF
0x0
0x1
0x0
Functional Description
484
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Hibernation Module
Care must be taken when using trim values that are near to the subseconds match value in the
HIBRTCSS register. It is possible when using trim values above 0x7FFF to receive two match interrupts
for the same counter value. In addition, it is possible when using trim values below 0x7FFF to miss a
match interrupt.
In the case of a trim value above 0x7FFF, when the RTCSSC value in the HIBRTCSS register reaches
0x7FFF, the RTCC value increments from 0x0 to 0x1 while the RTCSSC value is decreased by the trim
amount. The RTCSSC value is counted up again to 0x7FFF before rolling over to 0x0 to begin counting
up again. If the match value is within this range, the match interrupt is triggered twice. For example, as
shown in
, if the match interrupt was configured with RTCM0 = 0x1 and RTCSSM = 0x7FFD,
two interrupts would be triggered.
Figure 6-5. Counter Behavior with a TRIM Value of 0x8002
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
, if the match interrupt was configured with
RTCM0 = 0x1 and RTCSSM = 0x2, an interrupt would never be triggered.
Figure 6-6. Counter Behavior with a TRIM Value of 0x7FFC
6.3.6 Tamper
The Tamper module provides a user with mechanisms to detect, respond to, and log system tampering
events. The Tamper module is designed to be low power and operate either from a battery or the MCU I/O
voltage supply. This module is a submodule of the Hibernate module.
6.3.6.1
Tamper Block Diagram
shows the Tamper block diagram.