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Rev. 1.00
450 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)
Interrupts and Status
The USART can generate interrupts when the following event occurs and corresponding interrupt
enable bits are set:
▄
Receive FIFO time-out interrupt: An interrupt will be generated when the USART receive FIFO
is not empty and does not receive a new data package during the specified time-out interval.
▄
Receiver line status interrupts: The interrupts will be generated when the USART receiver
overrun error, parity error, framing error and break events occur.
▄
Transmit FIFO threshold level interrupt: An interrupt will be generated when the data to be
transmitted in the USART Transmit FIFO is less than the specified threshold level.
▄
Transmit complete interrupt: An interrupt will be generated when the Transmit FIFO is empty
and the content of the transmit shift register (TSR) is also completely shifted.
▄
Receive FIFO threshold level interrupt: An interrupt will be generated when the FIFO received
data amount has reached the specified threshold level.
Register Map
The following table shows the USART registers and reset values.
Table 52. USART Register Map
Register
Offset
Description
Reset Value
USRDR
0x000
USART Data Register
0x0000_0000
USRCR
0x004
USART Control Register
0x0000_0000
USRFCR
0x008
USART FIFO Control Register
0x0000_0000
USRIER
0x00C
USART Interrupt Enable Register
0x0000_0000
USRSIFR
0x010
USART Status & Interrupt Flag Register
0x0000_0180
USRTPR
0x014
USART Timing Parameter Register
0x0000_0000
IrDACR
0x018
USART IrDA Control Register
0x0000_0000
RS485CR
0x01C
USART RS485 Control Register
0x0000_0000
SYNCR
0x020
USART Synchronous Control Register
0x0000_0000
USRDLR
0x024
USART Divider Latch Register
0x0000_0010
USRTSTR
0x028
USART Test Register
0x0000_0000