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Rev. 1.00
468 of 486
July 31, 2018
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F50231/HT32F50241
22 Universal
Asynchronous Receiver T
ransmitter (UART)
22 Universal
Asynchronous Receiver T
ransmitter (UART)
Table 54. Baud Rate Deviation Error Calculation – CK_UART = 10 MHz
Baud Rate
CK_UART = 10 MHz
No.
Kbps
Actual
BRD
Deviation Error Rate
1
2.4
2.4
4167
-0.01%
2
9.6
9.6
1042
-0.03%
3
19.2
19.2
521
-0.03%
4
57.6
57.6
174
-0.22%
5
115.2
114.9
87
-0.22%
6
230.4
232.6
43
0.94%
7
460.8
454.5
22
-1.36%
8
625
625
16
0%
Interrupts and Status
The UART can generate interrupts when the following event occurs and the corresponding
interrupt enable bits are set:
▄
Receiver line status interrupts: The interrupts are generated when the overrun error, parity error,
framing error or break event occurs for the UART receiver.
▄
Transmit data register empty interrupt: An interrupt is generated when the content of the transmit
data register is transferred to the transmit shift register (TSR).
▄
Transmit complete interrupt: An interrupt is generated when the transmit data register (TDR) is
empty and the content of the transmit shift register (TSR) is also completely shifted.
▄
Receive data ready interrupt: An interrupt is generated when the content of the receive shift
register RDR has been transferred to the URDR register and is ready to read.
Register Map
The following table shows the UART registers and reset values.
Table 55. UART Register Map
Register
Offset
Description
Reset Value
URDR
0x000
UART Data Register
0x0000_0000
URCR
0x004
UART Control Register
0x0000_0000
URIER
0x00C
UART Interrupt Enable Register
0x0000_0000
URSIFR
0x010
UART Status & Interrupt Flag Register
0x0000_0180
URDLR
0x024
UART Divider Latch Register
0x0000_0010
URTSTR
0x028
UART Test Register
0x0000_0000