
RM0008
Universal synchronous asynchronous receiver transmitter (USART)
Doc ID 13902 Rev 12
797/1096
27.6.5
Control register 2 (USART_CR2)
Address offset: 0x10
Reset value: 0x0000
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
Res.
LINEN
STOP[1:0]
CLK
EN
CPOL
CPHA
LBCL
Res.
LBDIE
LBDL
Res.
ADD[3:0]
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bits 31:15 Reserved, forced by hardware to 0.
Bit 14
LINEN
: LIN mode enable
This bit is set and cleared by software.
0: LIN mode disabled
1: LIN mode enabled
The LIN mode enables the capability to send LIN Synch Breaks (13 low bits) using the SBK
bit in the USART_CR1 register, and to detect LIN Sync breaks.
Bits 13:12
STOP
: STOP bits
These bits are used for programming the stop bits.
00: 1 Stop bit
01: 0.5 Stop bit
10: 2 Stop bits
11: 1.5 Stop bit
The 0.5 Stop bit and 1.5 Stop bit are not available for UART4 & UART5.
Bit 11
CLKEN
: Clock enable
This bit allows the user to enable the CK pin.
0: CK pin disabled
1: CK pin enabled
This bit is not available for UART4 & UART5.
Bit 10
CPOL
: Clock polarity
This bit allows the user to select the polarity of the clock output on the CK pin in synchronous
mode. It works in conjunction with the CPHA bit to produce the desired clock/data
relationship
0: Steady low value on CK pin outside transmission window.
1: Steady high value on CK pin outside transmission window.
This bit is not available for UART4 & UART5.
Bit 9
CPHA
: Clock phase
This bit allows the user to select the phase of the clock output on the CK pin in synchronous
mode. It works in conjunction with the CPOL bit to produce the desired clock/data
relationship (see figures
)
0: The first clock transition is the first data capture edge.
1: The second clock transition is the first data capture edge.
This bit is not available for UART4 & UART5.