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Rev. 1.00
142 of 486
July 31, 2018
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F50231/HT32F50241
9
Alternate Function Input / Output Control Unit (AFIO)
9
Alternate Function Input / Output Control Unit (AFIO)
Register Descriptions
EXTI Source Selection Register 0 – ESSR0
This register specifies the I/O selection of EXTI0 ~ EXTI7.
Offset:
0x000
Reset value: 0x0000_0000
31
30
29
28
27
26
25
24
EXTI7PIN
EXTI6PIN
Type/Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0
23
22
21
20
19
18
17
16
EXTI5PIN
EXTI4PIN
Type/Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0
15
14
13
12
11
10
9
8
EXTI3PIN
EXTI2PIN
Type/Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0
7
6
5
4
3
2
1
0
EXTI1PIN
EXTI0PIN
Type/Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0
Bits
Field
Descriptions
[31:0]
EXTInPIN[3:0] EXTIn Pin Selection (n = 0 ~ 7)
0000: PA Bit n is selected as EXTIn source signal
0001: PB Bit n is selected as EXTIn source signal
0010: PC Bit n is selected as EXTIn source signal
Others: Reserved
Note: Since not all GPIO pins are available in all products and package types,
refer to the pin assignment section for detailed pin information. The
EXTInPIN [3:0] field setting is invalid when the corresponding pin is not
available.