ST STM32F405 Reference Manual page 832

Real-time clock (RTC)
26.6.17 RTC tamper and alternate function configuration register
(RTC_TAFCR)
Address offset: 0x40
Backup domain reset value: 0x0000 0000
System reset: not affected
31 30 29 28
15 14 13 12
TAMP- TAMP-
TAMPFLT[1:0]
PUDIS PRCH[1:0]
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Bits 31:19 Reserved. Always read as 0.
Bit 18 ALARMOUTTYPE: RTC_ALARM output type
Bit 17 TSINSEL: TIMESTAMP mapping
Bit 16 TAMP1INSEL: TAMPER1 mapping
Note: TAMP1E must be reset when TAMP1INSEL is changed to avoid unwanted setting of
Bit 15 TAMPPUDIS: TAMPER pull-up disable
1: Disable precharge of tamper pins
Note:
Bits 14:13 TAMPPRCH[1:0]: Tamper precharge duration
832/1749
27 26 25
Reserved
11 10 9
TAMPFREQ[2:0]
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0: RTC_ALARM is an open-drain output
1: RTC_ALARM is a push-pull output
0: RTC_AF1 used as TIMESTAMP
1: RTC_AF2 used as TIMESTAMP
0: RTC_AF1 used as TAMPER1
1: RTC_AF2 used as TAMPER1
TAMP1F.
This bit determines if each of the tamper pins are pre-charged before each sample.
0: Precharge tamper pins before sampling (enable internal pull-up)
These bit determines the duration of time during which the pull-up/is activated before each
sample. TAMPPRCH is valid for each of the tamper inputs.
0x0: 1 RTCCLK cycle
0x1: 2 RTCCLK cycles
0x2: 4 RTCCLK cycles
0x3: 8 RTCCLK cycles
24 23 22 21
8 7 6 5
TAMPT
S
Reserved
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RM0090 Rev 18
20 19 18
ALARMOUT
TYPE
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4 3 2
TAMP2 TAMP2
TAMPIE
-TRG E
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RM0090
17 16
TSIN TAMP1
SEL INSEL
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1 0
TAMP1 TAMP1
TRG E
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