GigaDevice Semiconductor GD32VF103 - Page 72

GD32VF103 User Manual
72
1000: CK_PLL1 clock selected
1001: CK_PLL2 clock divided by 2 selected
1010: EXT1 selected
1011: CK_PLL2 clock selected
23:22
USBFSPSC[1:0]
USBFS clock prescaler selection
Set and reset by software to control the USBFS clock prescaler value. The USBFS
clock must be 48MHz. These bits can’t be reset if the USBFS clock is enabled.
00: CK_USBFS = CK_PLL / 1.5
01: CK_USBFS = CK_PLL
10: CK_USBFS = CK_PLL / 2.5
11: CK_USBFS = CK_PLL / 2
21:18
PLLMF[3:0]
The PLL clock multiplication factor
Bit 29 of RCU_CFG0 and these bits are written by software to define the PLL
multiplication factor
Caution: The PLL output frequency must not exceed 108 MHz
00000: (PLL source clock x 2)
00001: (PLL source clock x 3)
00010: (PLL source clock x 4)
00011: (PLL source clock x 5)
00100: (PLL source clock x 6)
00101: (PLL source clock x 7)
00110: (PLL source clock x 8)
00111: (PLL source clock x 9)
01000: (PLL source clock x 10)
01001: (PLL source clock x 11)
01010: (PLL source clock x 12)
01011: (PLL source clock x 13)
01100: (PLL source clock x 14)
01101: (PLL source clock x 6.5)
01110: (PLL source clock x 16)
01111: (PLL source clock x 16)
10000: (PLL source clock x 17)
10001: (PLL source clock x 18)
10010: (PLL source clock x 19)
10011: (PLL source clock x 20)
10100: (PLL source clock x 21)
10101: (PLL source clock x 22)
10110: (PLL source clock x 23)
10111: (PLL source clock x 24)
11000: (PLL source clock x 25)
11001: (PLL source clock x 26)
11010: (PLL source clock x 27)
11011: (PLL source clock x 28)