![ARTERY AT32F435 Series Reference Manual Download Page 219](http://html1.mh-extra.com/html/artery/at32f435-series/at32f435-series_reference-manual_2977592219.webp)
AT32F435/437
Series Reference Manual
2022.11.11
Page 219
Rev 2.03
Bit 10
CLKPOL
0x0
rw
Clock polarity
In synchronous mode or Smartcard mode, this bit is used
to select the polarity of the clock output on the clock pin in
idle state.
0: Clock output low
1: Clock output high
Bit 9
CLKPHA
0x0
rw
Clock phase
This bit is used to select the phase of the clock output on
the clock pin in synchronous mode or Smartcard mode.
0: Data capture is done on the first clock edge.
1: Data capture is done on the second clock edge.
Bit 8
LBCP
0x0
rw
Last bit clock pulse
This bit is used to select whether the clock pulse of the last
data bit transmitted is output on the clock pin in
synchronous mode.
0: The clock pulse of the last data bit is no output on the
clock pin.
1: The clock pulse of the last data bit is output on the clock
pin.
Bit 7
Reserved
0x0
resd
Kept at its default value.
Bit 6
BFIEN
0x0
rw
Brake frame interrupt enable
0: Disabled
1: Enabled
Bit 5
BFBN
0x0
rw
Brake frame bit num
This bit is used to select 11-bit or 10-bit brake frame.
0: 10-bit brake frame
1: 11-bit brake frame
Bit 4
IDBN
0x0
rw
Identification bit num
This bit is used to select ID bit number.
0: 4 bit
1: Data bit - 1 bit
Note: When this bit is set, in 7, 8 or 8-bit data mode, the
ID bit number is the lower 6, 7 or 8 bit, respectively.
Bit 3: 0
IDL
0x0
rw
USART identification
This field holds the lower four bits of USART ID. It is
configurable.
Note: These three bits (CLKPOL, CLKPHA and LBCP) should not be changed while the transmission
is enabled.
12.12.6 Control register3 (USART_CTRL3)
Bit
Register
Reset value
Type
Description
Bit 31: 16 Reserved
0x0000
resd
Forced 0 by hardware.
Bit 15
DEP
0x0
rw
DE polarity selection
0: High level active
1: Low level active
Bit 14
RS485EN
0x0
rw
RS485 enable
This bit is used to enable RS485 mode. In RS485 mode,
the USART controls the transfer direction of the external
receiver/transmitter through the DE signal.
0: RS485 mode disabled. The control signal DE output is
disabled. RTS pin is used in RS232 mode.
1: RS485 mode enabled. The control signal DE outputs on
the RTS pin.
Bit 13 : 11 Reserved
0x0
resd
Forced 0 by hardware.
Bit 10
CTSCFIEN
0x0
rw
CTSCF interrupt enable
0: CTSCF interrupt disabled
1: CTSCF interrupt enabled
Bit 9
CTSEN
0x0
rw
CTS enable
0: CTS is disabled.
1: CTS is enabled.
Bit 8
RTSEN
0x0
rw
RTS enable
0: RTS is disabled.
1: RTS is enabled.