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AT32F413
Series Reference Manual
2022.06.27
Page 266
Rev 2.00
18.4.2 RTC calibration register (BPR_ RTCCAL)
Bit
Register
Reset value
Type
Description
Bit 15: 10 Reserved
0x00
resd
Kept at its default value.
Bit 9
OUTSEL
0x0
rw
Output selection
This bit is used to select either the RTC alarm event or the
second event.
0: RTC alarm event output
1: Second event output
Note: This bit is cleared only by a battery powered domain
reset.
Bit 8
OUTEN
0x0
rw
Output enable
0: Disabled
1: Enabled
Note: This bit is cleared only by a battery powered domain
reset. It is used to enable the event that is output on the
TAMPER pin. The TAMPER function can not be used if the
output is enabled.
Bit 7
CALOUT
0x0
rw
Calibration clock output
0: No effect
1: Output the RTC clock with a frequency divided by 64 on
the TAMPER pin.
The TAMPER function can not be used when the
calibration clock output is enabled.
Note: This bit is cleared when the VDD supply is powered
off.
Bit 6: 0
CALVAL
0x00
rw
Calibration value
This value indicates the number of clock filtered in one
cycle (2
20
clocks). The clock frequency is reduced with a
minium accuracy of 1000000/2
20
ppm. The RTC clock can
be slowed down from 0 to 121 ppm.
18.4.3 BPR control register (BPR_ CTRL)
Bit
Register
Reset value
Type
Description
Bit 15: 2
Reserved
0x0000
resd
Kept at its default value.
Bit 1
TPP
0x0
rw
TAMPER pin polarity
This bit defines the polarity of the TAMPER pin. The
contents in the data registers are cleared when an active
level is detected.
0: Active high
1: Active low
Note: To avoid unwanted tamper event, it is recommended
to modify the polarity of the TAMPER pin when it is
disabled.
Bit 0
TPEN
0x0
rw
TAMPER pin enable
0: Disabled. The TAMPER pin can be used as GPIO.
1: Enabled