SLAU723A October 2017 – October 2018 MSP432E401Y , MSP432E411Y
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 Figure 6-8. 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.