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GD32L23x User Manual
113
17:16
USART1SEL[1:0]
CK_USART1 clock source selection
This bit is set and reset by software.
00: CK_USART1 select CK_APB1
01: CK_USART1 select CK_SYS
10: CK_USART1 select CK_LXTAL
11: CK_USART1 select CK_IRC16MDIV
15:14
Reserved
Must be kept at reset value
13
USBDSEL
CK_USBD clock source selection
This bit is set and reset by software.
0: CK_USBD select CK_IRC48M
1: CK_ USBD select CK_PLL
12:11
LPUARTSEL[1:0]
LPUART clock source selection
This bit is set and reset by software.
00: CK_LPUART select CK_APB1
01: CK_LPUART select CK_SYS
10: CK_LPUART select CK_LXTAL
11: CK_LPUART select CK_IRC16MDIV
10:9
LPTIMERSEL[1:0]
CK_LPTIMER clock source selection
This bit is set and reset by software.
00: CK_LPTIMER select CK_APB2
01: CK_LPTIMER select CK_IRC32K
10: CK_LPTIMER select CK_LXTAL
11: CK_LPTIMER select CK_IRC16MDIV
8
ADCSEL
CK_ADC clock source selection
This bit is set and reset by software.
0: CK_ADC select CK_IRC16M
1: CK_ADC select CK_APB2 which is divided by
2, 4, 6, 8,10,12,14,16 or by the
clock of AHB divided by 3, 5, 7, 9,11,13,15,17
7:6
I2C2SEL[1:0]
CK_I2C2 clock source selection
00: CK_I2C2 select CK_APB1
01: CK_I2C2 select CK_SYS
10/11: CK_I2C2 select CK_IRC16MDIV
5:4
I2C1SEL[1:0]
CK_I2C1 clock source selection
00: CK_I2C1 select CK_APB1
01: CK_I2C1 select CK_SYS
10/11: CK_I2C1 select CK_IRC16MDIV
3:2
I2C0SEL[1:0]
CK_I2C0 clock source selection
00: CK_I2C0 select CK_APB1
01: CK_I2C0 select CK_SYS