GD32F403xx User Manual
238
14.2.
Window watchdog timer (WWDGT)
14.2.1.
Overview
The window watchdog timer (WWDGT) is used to detect system f ailures due to software
malf unctions. After the window watchdog timer starts, the value of down counter reduces
progressively. The watchdog timer causes a reset when the counter reached 0x3F (the CNT[6]
bit has been cleared). The watchdog timer also causes a reset when the counter is refreshed
bef ore the counter reached the window register value. So the software should ref resh the
counter in a limited window. The window watchdog timer generates an early wakeup status
f lag when the counter reaches 0x40. Interrup occurs if it is enabled.
The window watchdog timer clock is prescaled f rom the APB1 clock. The window watchdog
timer is suitable for the situation that requires an accurate timing.
14.2.2.
Characteristics
◼
Programmable free-running 7-bit downcounter.
◼
Generate reset in two conditions when WWDGT is enabled:
–
Reset when the counter reached 0x3F.
–
The counter is ref reshed when the value of the counter is greater than the window
register value.
◼
Early wakeup interrupt (EWI): if the watchdog is started and the interrupt is enabled, the
interrupt occurs when the counter reaches 0x40.
◼
WWDGT debug mode, the WWDGT can stop or continue to work in debug mode.
14.2.3.
Function overview
If the window watchdog timer is enabled (set the WDGTEN bit in the WWDGT_CTL), the
watchdog timer causes a reset when the counter reaches 0x3F (the CNT[6] bit has been
cleared), or the counter is refreshed before the counter reaches the window register value.
Figure 14-2. Window watchdog timer block diagram
Reset
Write WWDGT_CTL
CNT>WIN
CNT[6]=0
Reset
PCLK1/4096
Prescaler
/1/2/4/8
7-Bit Down Counter
CNT
Window WIN
WDGTEN
Содержание GD32F403 Series
Страница 1: ...GigaDevice Semiconductor Inc GD32F403xx Arm Cortex M4 32 bit MCU User Manual Revision 2 6 Jul 2022 ...
Страница 177: ...GD32F403xx UserManual 177 Peripheral Channel 0 Channel 1 Channel 2 Channel 3 Channel 4 SDIO SDIO ...
Страница 217: ...GD32F403xx UserManual 217 ensures that no conversion is in progress ...