GD32F403xx User Manual
104
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Bits
Fields
Descriptions
31:17
Reserved
Must be kept at reset value.
16
BKPRST
Backup domain reset
This bit is set and reset by software.
0: No reset
1: Resets Backup domain
15
RTCEN
RTC clock enable
This bit is set and reset by software.
0: Disabled RTC clock
1: Enabled RTC clock
14:10
Reserved
Must be kept at reset value.
9:8
RTCSRC[1:0]
RTC clock entry selection
Set and reset by software to control the RTC clock source. Once the RTC clock
source has been selected, it cannot be changed anymore unless the backup
domain is reset.
00: No clock selected
01: CK_LXTAL selected as RTC source clock
10: CK_IRC40K selected as RTC source clock
11: (CK_HXTAL / 128) selected as RTC source clock
7:5
Reserved
Must be kept at reset value.
4:3
LXTALDRI[1:0]
LXTAL drive capability
Set and reset by software. Backup domain reset resets this value.
00: Lower driving capability
01: Medium low driving capability
10: Medium high driving capability
11: Higher driving capability (reset value)
Note
: The LXTALDRI is not in bypass mode.
2
LXTALBPS
LXTAL bypass mode enable
Set and reset by software.
0: Disable the LXTAL Bypass mode
1: Enable the LXTAL Bypass mode
1
LXTALSTB
Low speed crystal oscillator stabilization flag
Set by hardware to indicate if the LXTAL output clock is stable and ready for use.
0: LXTAL is not stable
1: LXTAL is stable
0
LXTALEN
LXTAL enable
Set and reset by software.