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Rev. 1.00
457 of 576
January 28, 2022
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F54231/HT32F54241/HT32F54243/HT32F54253
21 Serial Peripheral Interface (SPI)
21 Serial Peripheral Interface (SPI)
Register Descriptions
SPI Control Register 0 – SPICR0
This register specifies the SEL control and the SPI enable bits.
Offset:
0x000
Reset value: 0x0000_0000
31
30
29
28
27
26
25
24
Reserved
Type/Reset
23
22
21
20
19
18
17
16
Reserved
Type/Reset
15
14
13
12
11
10
9
8
SELHT
GUADT
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
GUADTEN DUALEN Reserved
SSELC
SELOEN RXDMAE TXDMAE
SPIEN
Type/Reset RW 0 RW 0
RW 0 RW 0 RW 0 RW 0 RW 0
Bits
Field
Descriptions
[15:12]
SELHT
Chip Select Hold Time
0x0: 1/2 SCK
0x1: 1 SCK
0x2: 3/2 SCK
0x3: 2 SCK
....
Note that SELHT is for master mode only.
[11:8]
GUADT
Guard Time
GUADTEN = 1
0x0: 1 SCK
0x1: 2 SCK
0x2: 3 SCK
...
Note that GUADT is for master mode only.
[7]
GUADTEN
Guard Time Enable
0: Guard Time is 1/2 SCK
1: When this bit is set, guard time can be controlled by GUADT
Note that GUADTEN is for master mode only.
[6]
DUALEN
Dual Mode Enable
0: Dual Mode is disabled
1: Dual Mode is enabled
The control bit is used to support the dual output read mode of the series SPI NOR
Flash. When this bit is set and the MOSI signal will change the direction from output
to input and receive the series data stream. That means the DUALEN control bit is
only for master mode.