Clock Source Status Register - Ckst - Holtek HT32F50231 User Manual

32-Bit Arm ® Cortex ® -M0+ MCU
HT32F50231/HT32F50241
Clock Source Status Register – CKST
This register specifies status of clock source.
Offset: 0x034
Reset value: 0x0100_0003
31
Type/Reset
23
Type/Reset
15
Type/Reset
7
Type/Reset
Bits Field
[26:24] HSIST
[17:16] HSEST
[2:0] CKSWST
Rev. 1.00
30 29 28
Reserved
22 21 20
Reserved
14 13 12
6 5 4
Reserved
Descriptions
Internal High Speed Clock Occupation Status (CK_HSI)
xx1: HSI is used by System Clock (CK_SYS) (SW = 0x3)
x1x: Reserved
1xx: HSI is used by Clock Monitor
External High Speed Clock Occupation Status (CK_HSE)
x1: HSE is used by System Clock (CK_SYS) (SW = 0x2)
1x: Reserved
Clock Switch Status
00x: Reserved
010: CK_HSE as system clock
011: CK_HSI as system clock
110: CK_LSE as system clock
111: CK_LSI as system clock
The fields are status to indicate which clock source is using as system clock currently.
89 of 486
27 26
HSIST
RO 0 RO
19 18
RO
11 10
Reserved
3 2
CKSWST
RO 0 RO
25 24
0 RO 1
17 16
HSEST
0 RO 0
9 8
1 0
1 RO 1
July 31, 2018