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Rev. 1.00
452 of 486
July 31, 2018
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F50231/HT32F50241
21 Universal Synchronous
Asynchronous Receiver T
ransmitter (USART)
21 Universal Synchronous
Asynchronous Receiver T
ransmitter (USART)
USART Control Register – USRCR
The register specifies the serial parameters such as data length, parity and stop bit for the USART. It also
contains the USART enable control bits together with the USART mode and data transfer mode selections.
Offset:
0x004
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
RTS
BCB
SPE
EPE
PBE
NSB
WLS
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
Reserved URRXEN
URTXEN
HFCEN
TRSM
MODE
Type/Reset
RW 0 RW 0 RW 0 RW 0 RW 0 RW 0
Bits
Field
Descriptions
[15]
RTS
Request-To-Send Signal
0: Drive USART RTS pin to logic 1
1: Drive USART RTS pin to logic 0
Note that the RTS bit is used to control the USART RTS pin status when the HFCEN
bit is reset.
When the HFCEN bit is set, this RTS bit is read only, which indicates the pin status
that is controlled by hardware flow control function.
[14]
BCB
Break Control Bit
When this bit is set 1, the serial data output on the USART TX pin will be forced to
the Spacing State (logic 0). This bit acts only on USART TX output pin and has no
effect on the transmitter logic.
[13]
SPE
Stick Parity Enable
0: Disable stick parity
1: Stick Parity bit is transmitted
This bit is only available when the PBE bit is set to 1. If both the PBE and SPE bits
are set to 1 and the EPE bit is cleared to 0, the transmitted parity bit will be stuck to
1. However, when the PBE and SPE bits are set to 1 and also the EPE bit is set to 1,
the transmitted parity bit will be stuck to 0.
[12]
EPE
Even Parity Enable
0: Odd number of logic 1’s are transmitted or checked in the data word and parity
bits
1: Even number of logic 1’s are transmitted or checked in the data word and
parity bits
This bit is only available when PBE is set to 1.
[11]
PBE
Parity Bit Enable
0: Parity bit is not generated (transmitted data) or checked (received data) during
transfer
1: Parity bit is generated or checked during transfer
Note: When the WLS field is set to “10” to select the 9-bit data format, writing to the
PBE bit has no effect.