GD32W51x User Manual
198
30
SS_TYPE
PLL spread spectrum modulation type select
0: Center spread selected
1: Dow n spread selected
29:28
Reserved
Must be kept at reset value.
27:13
MODSTEP[14:0]
These bits configure PLL spread spectrum modulation profile amplitude and
frequency. The follow ing criteria must be met: MODSTEP*MODCNT≤2
16
-1
12:0
MODCNT[12:0]
These bits configure PLL spread spectrum modulation profile amplitude and
frequency. The follow ing
criteria must be met: MODSTEP*MODCNT≤2
16
-1
6.5.23.
PLL clock configuration register (RCU_PLLCFG)
Address offset: 0x84
Reset value: 0x0300 0000
To configure the PLLI2S clock, refer to the following formula:
CK_PLLI2SVCOSRC = CK_PLLI2SSRC / PLLI2SPSC
CK_PLLI2SVCO = CK_PLLI2SVCOSRC × PLLI2SN
CK_PLLI2S = CK_PLLI2SVCO / PLLI2SDIV
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
PLLDIGFSYSDIV[5:0]
PLLDIGOSEL[1:0]
Reserved
PLLI2SPSC[2:0]
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
PLLI2SN[6:0]
Reserved
PLLI2SDIV[5:0]
rw
rw
Bits
Fields
Descriptions
31:26
PLLDIGFSYSD IV[5:0
]
PLLDIG clock divider factor for system clock
Set and reset by softw are to control the PLLDIG clock divider factor for system
clock.
000000: PLLDIG clock divided by 1 for system clock
000001: PLLDIG clock divided by 2 for system clock
000010: PLLDIG clock divided by 2 for system clock
…
111111: PLLDIG clock divided by 64 for system clock
25:24
PLLDIGOSEL[1:0]
PLLDIG output frequency select
00: selected 192Mhz as PLLDIG output frequency
01: selected 240Mhz as PLLDIG output frequency
10: selected 320Mhz as PLLDIG output frequency.
11: selected 480Mhz as PLLDIG output frequency