DocID025202 Rev 7
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RM0365
Real-time clock (RTC)
764
27.6.5 RTC
prescaler
register (RTC_PRER)
This register must be written in initialization mode only. The initialization must be performed
in two separate write accesses. Refer to
Calendar initialization and configuration on
.
This register is write protected. The write access procedure is described in
Address offset: 0x10
Backup domain reset value: 0x007F 00FF
System reset: not affected
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
PREDIV_A[6:0]
rw
rw
rw
rw
rw
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Res.
PREDIV_S[14:0]
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bits 31:23 Reserved, must be kept at reset value
Bits 22:16
PREDIV_A[6:0]
: Asynchronous prescaler factor
This is the asynchronous division factor:
ck_apre frequency = RTCCLK frequency/(P1)
Bit 15 Reserved, must be kept at reset value.
Bits 14:0
PREDIV_S[14:0]
: Synchronous prescaler factor
This is the synchronous division factor:
ck_spre frequency = ck_apre frequency/(P1)