GD32W51x User Manual
152
6.
Reset and clock unit (RCU)
6.1.
Reset control unit (RCTL)
6.1.1.
Overview
GD32W51x Reset Control includes the control of three kinds of reset: power reset, system
reset and backup domain reset. The power reset, known as a cold reset, resets the full system
except the Backup domain. The system reset resets the processor core and peripheral IP
components except for the SW-DP controller and the Backup domain. The backup domain
reset resets the Backup domain. The resets can be triggered by an external signal, internal
events and the reset generators. More information about these resets will be described in the
following sections.
6.1.2.
Function overview
Power reset
The Power reset is generated by either an external reset as Power On and Power Down reset
(POR/PDR reset), Brownout reset (BOR reset) or by the internal reset generator when exiting
Standby mode. The power reset sets all registers to their reset values exc ept the Backup
domain. The Power reset whose active signal is low, it will be de-asserted when the internal
LDO voltage regulator is ready to provide 1.2V power.
System reset
A system reset is generated by the following events:
A power reset (POWER_RSTn)
A external pin reset (NRST)
A window watchdog timer reset (WWDGT_RSTn)
A free watchdog timer reset (FWDGT_RSTn)
The SYSRESETREQ bit in Cortex™-M33 Application Interrupt and Reset Control
Register is set (SW_RSTn)
Reset generated when entering Standby mode when resetting NRSTSTDBY bit in
EFUSE_USER_CTL register (NRSTSTDBY)
Reset generated when entering Deep-sleep mode when resetting NRSTDPSLP bit in
EFUSE_USER_CTL register (NRSTDPSTDBY)
A system reset resets the processor core and peripheral IP components except for the SW-
DP controller and the Backup domain.
A system reset pulse generator guarantees low level pulse duration of 20 μs for each reset
source (external or internal reset).