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Select "seconds" as the time period of the alarm, and only when the
synchronous prescaler value is greater than 2, can the alarm operate normally.
Timestamp
RTC supports timestamp function and the RTC_TS pin works together with the
timestamp register.
The timestamp polarity is detected through TSETECFG bit of the register
RTC_CTRL. When RTC_TS pin recognizes the external timestamp edge signal,
RTC will automatically latch the current calendar in the subsecond, time and date
timestamp registers, and the timestamp flag bit TSFLG will be set to 1. If the
timestamp interrupt is enabled, the timestamp interrupt processing will be
triggered.
When TSFLG flag bit is set to 1, and a timestamp event occurs, the timestamp
will overrun, and the flag bit TSOVRFLG will be set to 1. If a timestamp event is
detected once TSFLG flag is cleared, both TSFLG and TSOVRFLG flags will be
set to 1.
Tamper Detection
Tamper detection is a kind of data self-destruction protection device to prevent
data leakage caused by tamper. Through the hardware circuit design, the tamper
detection signal is transmitted to the tamper detection pin.
Tamper detection has multiple tamper detection pins, and each pin is enabled by
a register bit separately. In order to detect real tamper events better, signal
filtering can be configured, and tamper detection polarity can be configured for
each pin.
Tamper detection polarity
The low level/rising edge and high level/falling edge can be selected as tamper
detection polarity through TPxALCFG bit in the register RTC_TACFG.
Tamper signal filter
TPSFSEL bit of the register RTC_TACFG is used to configure the sampling
frequency of tamper detection, and TPFCSEL bit of RTC_TACFG is used to
configure after how many valid tamper signals are detected continuously, a
tamper event can be generated.
In particular, if a tamper signal has been generated on the tamper detection pin
before the tamper detection pin is enabled, a tamper event will be immediately
generated on the enabled tamper detection pin.
Tamper timestamp
At some times, in order to record the tamper detection events, RTC can latch the
current tamper timestamp and this function can be enabled quickly through
TPTSEN bit of the register RTC_TACFG, not needing to enable the timestamp
function additionally.
Automatic Wake-up
Available only on APM32F030xC device
.
Compared with RTC alarm, the hardware structure of the automatic wake-up is
simpler, and it has no complicated configuration process of RTC alarm, so it is a
