GD32A50x User Manual
122
2
Reserved
Must be kept at reset value.
1
IRC8MSTB
IRC8M high speed internal oscillator stabilization flag
Set by hardware to indicate if the IRC8M oscillator is stable and ready for use.
0: IRC8M oscillator is not stable
1: IRC8M oscillator is stable
0
IRC8MEN
Internal high speed oscillator enable
Set and reset by software. This bit cannot be reset if the IRC8M clock is used as
the system clock. Set by hardware when leaving Deep-sleep or Standby mode or
the HXTAL clock is stuck at a low or high state when HXTALCKM is set.
0: Internal 8 MHz RC oscillator disabled
1: Internal 8 MHz RC oscillator enabled
5.3.2.
Configuration register 0 (RCU_CFG0)
Address offset: 0x04
Reset value: 0x0002 0000
This register can be accessed by byte(8-bit), half-word(16-bit) and word(32-bit)
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
PLLDV
CKOUTDIV[2:0]
PLLMF[4]
CKOUTSEL[2:0]
Reserved
PLLMF[3:0]
DPLL
PLLSEL
rw
rw
rw
rw
rw
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
APB2PSC[2:0]
APB1PSC[2:0]
AHBPSC[3:0]
SCSS[1:0]
SCS[1:0]
rw
rw
rw
r
rw
Bits
Fields
Descriptions
31
PLLDV
The CK_PLL divide by 1 or 2 for CK_OUT
0: CK_PLL divide by 2 for CK_OUT
1: CK_PLL divide by 1 for CK_OUT
30:28
CKOUTDIV[2:0]
The CK_OUT divider which the CK_OUT frequency can be reduced,
see bits 26:24 of RCU_CFG0 for CK_OUT.
000: The CK_OUT is divided by 1
001: The CK_OUT is divided by 2
010: The CK_OUT is divided by 4
011: The CK_OUT is divided by 8
100: The CK_OUT is divided by 16
101: The CK_OUT is divided by 32
110: The CK_OUT is divided by 64
111: The CK_OUT is divided by 128
27
PLLMF[4]
Bit 4 of PLLMF register
see bits 21:18 of RCU_CFG0.