
DocID024597 Rev 5
RM0351
Real-time clock (RTC)
1230
38.6.5 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)