GigaDevice Semiconductor GD32F3x0 - Page 475

GD32F3x0 User Manual
475
In standard mode, the RTF flag is set if no new start bit is detected for more than
the RT value after the last received character.
In smartcard mode, the CWT and BWT are implemented by this value. In this case,
the timeout measurement is started from the start bit of the last received character.
These bits can be written on the fly. The RTF flag will be set if the new value is
lower than or equal to the counter. These bits must only be programmed once per
received character.
18.4.7. Command register (USART_CMD)
Address offset: 0x18
Reset value: 0x0000 0000
This register has to be accessed by word (32-bit).
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
TXFCMD
RXFCMD
MMCMD
SBKCMD
Reserved
w
w
w
w
Bits
Fields
Descriptions
31:5
Reserved
Must be kept at reset value.
4
TXFCMD
Transmit data flush request
Writing 1 to this bit sets the TBE flag, to discard the transmit data.
This bit is reserved in USART1.
3
RXFCMD
Receive data flush command
Writing 1 to this bit clears the RBNE flag to discard the received data without
reading it.
2
MMCMD
Mute mode command
Writing 1 to this bit makes the USART into mute mode and sets the RWU flag.
1
SBKCMD
Send break command
Writing 1 to this bit sets the SBKF flag and makes the USART send a BREAK
frame, as soon as the transmit machine is idle.
0
Reserved
Must be kept at reset value.
18.4.8. Status register (USART_STAT)
Address offset: 0x1C
Reset value: 0x0000 00C0
This register has to be accessed by word (32-bit).