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Rev. 1.00
488 of 576
January 28, 2022
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F54231/HT32F54241/HT32F54243/HT32F54253
22 Universal Synchronous
Asynchronous Receiver T
ransmitter (USART)
USART Timing Parameter Register – USRTPR
This register contains the USART timing parameters including the transmitter time guard parameters and the
receive FIFO time-out value together with the RX FIFO time-out interrupt enable control.
Offset:
0x014
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
TG
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
RXTOEN
RXTOC
Type/Reset RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0 RW 0
Bits
Field
Descriptions
[15:8]
TG
Transmitter Time Guard
The transmitter time guard counter is driven by the baud rate clock. When the
TX FIFO transmits data, the counter is reset and then starts to count after a word
transmission has completed. Only when the counter content is equal to the TG
value, are further word transmission transactions allowed.
[7]
RXTOEN
Receive FIFO Time-Out Counter Enable
0: RX FIFO Time-Out Counter is disabled
1: RX FIFO Time-Out Counter is enabled
[6:0]
RXTOC
Receive FIFO Time-Out Counter Compare Value
The RX FIFO time-out counter is driven by the baud rate clock. When the RX FIFO
receives new data, the counter is reset and then starts to count. Once the time-out
counter content is equal to the time-out counter compare value RXTOC, an RX FIFO
time-out interrupt, RXTOI, will be generated if the RXTOIE bit in the USRIER register
is set to 1. New received data or the empty RX FIFO after being read will clear the
RX FIFO time-out counter.