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Rev. 1.00
33 of 576
January 28, 2022
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F54231/HT32F54241/HT32F54243/HT32F54253
1 Introduction
2 Document Conventions
2
2
Document Conventions
The conventions used in this document are shown in the following table.
Table 2. Document Conventions
Notation
Example
Description
0x
0x5a05
The number string with a 0x prefix indicates a hexadecimal
number.
0xnnnn_nnnn
0x2000_0100
32-bit Hexadecimal address or data.
b
b0101
The number string with a lowercase b prefix indicates a
binary number.
NAME [n]
ADDR [5]
Specific bit of NAME. NAME can be a register or field of
register. For example, ADDR [5] means bit 5 of ADDR
register (field).
NAME [m:n]
ADDR [11:5]
Specific bits of NAME. NAME can be a register or field of
register. For example, ADDR [11:5] means bit 11 to 5 of
ADDR register (field).
X
b10X1
Don’t care notation which means any value is allowed.
RW
RW 0 RW 0
19
18
PLLEN
HSEEN
Software can read and write to this bit.
RO
HSIRDY
RO 1 RO 0
3
2
HSERDY Software can only read this bit. A write operation will have
no effect.
RC
RC 0 RC 1
1
0
PORF
Software can only read this bit. A read operation will clear
it to 0 automatically.
WC
WC 0 WC 0
3
2
CKSF
Software can read this bit or clear it by writing 1. Writing 0
to it will have no effect.
W0C
W0C 0
1
0
MIF
Software can read this bit or clear it by writing 0. Writing 1
to it will have no effect.
WO
CH1CCG
WO 0 WO 0
1
0
CH0CCG Software can only write to this bit. A read operation always
returns 0.
Reserved
7
6
Reserved
Reserved bit(s) for future use. Data read from these bits
is not well defined and should be treated as random data.
Normally these reserved bits should be cleared to a 0
value. Note that reserved bit must be kept at reset value.
Word
Data length of a word is 32-bit.
Half-word
Data length of a half-word is 16-bit.
Byte
Data length of a byte is 8-bit.