Independent watchdog (IWDG)
RM0365
719/1080
DocID025202 Rev 7
26.4.4 Status
register
(IWDG_SR)
Address offset: 0x0C
Reset value: 0x0000 0000 (not reset by Standby mode)
Note:
If several reload, prescaler, or window values are used by the application, it is mandatory to
wait until RVU bit is reset before changing the reload value, to wait until PVU bit is reset
before changing the prescaler value, and to wait until WVU bit is reset before changing the
window value. However, after updating the prescaler and/or the reload/window value it is not
necessary to wait until RVU or PVU or WVU is reset before continuing code execution
except in case of low-power mode entry.
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.
WVU
RVU
PVU
r
r
r
Bits 31:3 Reserved, must be kept at reset value.
Bit 2
WVU:
Watchdog counter window value update
This bit is set by hardware to indicate that an update of the window value is ongoing. It is reset
by hardware when the reload value update operation is completed in the V
DD
voltage domain
(takes up to 5 RC 40 kHz cycles).
Window value can be updated only when WVU bit is reset.
This bit is generated only if generic “window” = 1
Bit 1
RVU:
Watchdog counter reload value update
This bit is set by hardware to indicate that an update of the reload value is ongoing. It is reset
by hardware when the reload value update operation is completed in the V
DD
voltage domain
(takes up to 5 RC 40 kHz cycles).
Reload value can be updated only when RVU bit is reset.
Bit 0
PVU:
Watchdog prescaler value update
This bit is set by hardware to indicate that an update of the prescaler value is ongoing. It is
reset by hardware when the prescaler update operation is completed in the V
DD
voltage
domain (takes up to 5 RC 40 kHz cycles).
Prescaler value can be updated only when PVU bit is reset.