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GD32L23x User Manual
267
mode or level detection mode with configurable filtering setting.
The purposes of the tamper detect configuration are the following:
1.
The default configuration will erase the RTC backup registers
2.
It can wakeup from DeepSleep and Standby modes, and generate an interrupt
3.
It is used for the low-power timers to generate a hardware trigger
RTC backup registers (RTC_BKPx)
The RTC backup registers are located in the VDD backup domain that remains powered-on
by V
BAT
even if V
DD
power is switched off. The wake up action from Standby Mode or System
Reset does not affect these registers.
These registers are only reset by detected tamper event and backup domain reset except if
the TPxNOERASE bit is set, or if TPxMASK is set in the RTC_TAMP register.
Tamper detection function initialization
RTC tamper detection function can be independently enabled on tamper input pin by setting
corresponding TPxEN bit. Tamper detection configuration is set before enable TPxEN bit.
TPxMASK =0:
The TPxF flag is set after the tamper event occurs on the pin with the following latency:
1.
When FLT is different from 0x0 (Level detection mode with configurable filtering), there
are three ck_apre cycles
2.
When TPTS is set (Timestamp on tamper event), there are three ck_apre cycles
3.
When FLT is reset (Edge detection mode on tamper input detection) and TPTS is reset,
there is no latency.
When TPxF is set during the latency, new tamper cannot be detected occurring on the same
pin.
TPxMASK=1:
When TPxF is set during the latency and 2.5 RTC clock additional, new tamper cannot be
detected occurring on the same pin.
Tamper event can generate an interrupt if tamper interrupt enable (TPIE) is set.when one or
more TPxMASK is set, TPIE can not be setting.
When TPIE is cleared, each tamper pin event interrupt can be enabled independently by
setting the corresponding TPxIE bit. When the corresponding TPxMASK is set, TPxIE cannot
be set.