GD32W51x User Manual
395
Figure 15-3. Window watchdog timing diagram
Write WWDG_CTL when CNT>WIN
cause a reset
CNT[6]=0 cause a reset
0x7F
Start
CNT[6:0]
0x3F
WIN
Write CNT
Start
Calculate the WWDGT timeout by using the formula below.
t
WWDGT
=t
PCLK1
×4096 ×2
PSC
×
(
CNT
[
5:0
]
+1
)
(ms) (13-1)
where:
t
WWDGT
: WWDGT timeout
t
PCLK1
: APB1 clock period measured in ms
The table below shows the minimum and maximum values of the t
WWDGT
.
Table 15-2. Min-max timeout value at 45 MHz (f
PCLK1
)
Prescaler divider
PSC[1:0]
Min tim eout value
CNT[6:0] =0x40
Max tim eout value
CNT[6:0]=0x7F
1/1
00
91.02
μs
5.83 ms
1/2
01
182.04
μs
11.65 ms
1/4
10
364.08
μs
23.30 ms
1/8
11
728.18
μs
46.60 ms
If the WWDGT_HOLD bit in DBG module is cleared, the WWDGT continues to work even the
Cortex™-M33 core halted (Debug mode). While the WWDGT_HOLD bit is set, the WWDGT
stops in Debug mode.