DocID018909 Rev 11
709/1731
RM0090
Window watchdog (WWDG)
710
22.6.2 Configuration
register (WWDG_CFR)
Address offset: 0x04
Reset value: 0x0000 007F
22.6.3 Status
register
(WWDG_SR)
Address offset: 0x08
Reset value: 0x0000 0000
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
EWI
WDGTB[1:0]
W[6:0]
rs
rw
rw
Bit 31:10 Reserved, must be kept at reset value.
Bit 9
EWI:
Early wakeup interrupt
When set, an interrupt occurs whenever the counter reaches the value 0x40. This interrupt is
only cleared by hardware after a reset.
Bits 8:7
WDGTB[1:0]:
Timer base
The time base of the prescaler can be modified as follows:
00: CK Counter Clock (PCLK1 div 4096) div 1
01: CK Counter Clock (PCLK1 div 4096) div 2
10: CK Counter Clock (PCLK1 div 4096) div 4
11: CK Counter Clock (PCLK1 div 4096) div 8
Bits 6:0
W[6:0]:
7-bit window value
These bits contain the window value to be compared to the downcounter.
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
EWIF
rc_w0
Bits 31:1 Reserved, must be kept at reset value.
Bit 0
EWIF:
Early wakeup interrupt flag
This bit is set by hardware when the counter has reached the value 0x40. It must be cleared
by software by writing ‘0’. A write of ‘1’ has no effect. This bit is also set if the interrupt is not
enabled.