HIBTPSTAT
Control
XOSC0
Tamper Log
HIBTPLOG
Tamper Event NMI
TMPR[3:0]
HIBTPCTL
HIBTPIO
Tamper Detect
and Filter
XOSC Fail
Detector
RTC
BBRAM Clear
HIB Wake
HIBTPCTL.TPEN
HIBTPCTL.TPEN
Functional Description
485
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Hibernation Module
Figure 6-7. Tamper Block Diagram
6.3.6.2
Functional Description
The Tamper module provides mechanisms to detect, respond, and log system tamper events. A tamper
event is detected by state transitions on up to four GPIOs. The module may respond to a tamper event by
clearing all or part of the hibernate module memory, generating a tamper event signal to the System
Control module. The event will also be logged with a RTC timestamp to allow for tamper investigation.
6.3.6.2.1 Tamper Detection
Qualified tamper events are detected through an XOSCn pin failure or through tamper I/O level matches
which pass through a glitch filter. Tamper I/O pad events are detected by comparing the level on a tamper
I/O pad with an expected value. The tamper I/O is sampled using the hibernate clock source and when the
glitch filtering is enabled, must be stable for approximately 100 ms. This provides debounce filtering of a
breakaway switch as a results of a drop impact. The tamper module contains one long glitch filter and one
short glitch filter which uses an OR of the inputs as shown in
. This implies if two Tamper inputs
are asserted and one deasserts, the glitch filter runs to time-out or until the second Tamper input is
deasserted. The glitch filter or tamper logging logic does not trigger again if the tamper event match
continues. The glitch filter resets on the deassertion of the tamper conditions or when a qualified tamper
event is logged.
If the XOSCn pins are enabled for use with the Hibernation module and subsequently fail, a tamper event
is detected and is indicated by the STATE field in the HIB Tamper Status (HIBTPSTAT) register. In
addition, the XOSCST and XOSCFAIL bits can be read for further details on the external oscillator source
state.