
RM0453 Rev 2
979/1454
RM0453
Independent watchdog (IWDG)
983
30.4.2 IWDG
prescaler
register (IWDG_PR)
Address offset: 0x04
Reset value: 0x0000 0000
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.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
PR[2:0]
rw
rw
rw
Bits 31:3 Reserved, must be kept at reset value.
Bits 2:0
PR[2:0]:
Prescaler divider
These bits are write access protected see
Section 30.3.5: Register access protection
. They
are written by software to select the prescaler divider feeding the counter clock. PVU bit of
the
IWDG status register (IWDG_SR)
must be reset in order to be able to change the
prescaler divider.
000: divider /4
001: divider /8
010: divider /16
011: divider /32
100: divider /64
101: divider /128
110: divider /256
111: divider /256
Note: Reading this register returns the prescaler value from the V
DD
voltage domain. This
value may not be up to date/valid if a write operation to this register is ongoing. For this
reason the value read from this register is valid only when the PVU bit in the
is reset.