![GigaDevice Semiconductor GD32E23 Series User Manual Download Page 100](http://html.mh-extra.com/html/gigadevice-semiconductor/gd32e23-series/gd32e23-series_user-manual_2225794100.webp)
GD32E23x User Manual
100
16
IRC28MDIV
IRC28M divider or not
0: IRC28M /2 used as ADC clock
1: IRC28M used as ADC clock
15:9
Reserved
Must be kept at reset value
8
ADCSEL
CK_ADC clock source selection
This bit is set and reset by software.
0: CK_ADC select CK_IRC28M
1: CK_ADC select CK_APB2 which is divided by 2,4,6,8 or. CK_AHB which is
divided by 3,5,7,9
7:2
Reserved
Must be kept at reset value
1:0
USART0SEL[1:0]
CK_USART0 clock source selection
This bit is set and reset by software.
00: CK_USART0 select CK_APB2
01: CK_USART0 select CK_SYS
10: CK_USART0 select CK_LXTAL
11: CK_USART0 select CK_IRC8M
4.3.14.
Control register 1 (RCU_CTL1)
Address offset: 0x34
Reset value: 0x0000 XX80 where X is undefined.
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
Reserved
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
IRC28MCALIB[7:0]
IRC28MADJ[4:0]
Reserved
IRC28MS
TB
IRC28ME
N
r
rw
r
rw
Bits
Fields
Descriptions
31:16
Reserved
Must be kept at reset value
15:8
IRC28MCALIB[7:0]
Internal 28M RC oscillator calibration value register
These bits are load automatically at power on.
7:3
IRC28MADJ[4:0]
Internal 28M RC oscillator clock trim adjust value
These bits are set by software. The trimming value is there bits (IRC28MADJ)
added to the IRC28MCALIB[7:0] bits. The trimming value should trim the IRC28M
to 28MHz ± 1%.
2
Reserved
Must be kept at reset value