DocID025202 Rev 7
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RM0365
Universal synchronous asynchronous receiver transmitter (USART)
901
29.8.12 USART register map
The table below gives the USART register map and reset values.
Bits 31:9 Reserved, must be kept at reset value.
Bits 8:0
TDR[8:0]
: Transmit data value
Contains the data character to be transmitted.
The TDR register provides the parallel interface between the internal bus and the output
shift register (see
).
When transmitting with the parity enabled (PCE bit set to 1 in the USART_CR1 register),
the value written in the MSB (bit 7 or bit 8 depending on the data length) has no effect
because it is replaced by the parity.
Note: This register must be written only when TXE=1.
Table 160. USART register map and reset values
Offset
Register
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0x00
USART_CR1
Res.
Res.
Res.
M1
EO
BI
E
RTO
IE
DEA
T
4
DEA
T
3
DEA
T
2
DEA
T
1
DEA
T
0
DEDT4
DEDT3
DEDT2
DEDT1
DEDT0
O
VER8
CMIE
MME
M0
W
AKE
PCE
PS
PEI
E
TXEI
E
TC
IE
RXNEIE
IDL
E
IE
TE
RE
UES
M
UE
Reset value
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0
0
0 0 0 0 0 0 0 0 0
0
0
0
0x04
USART_CR2
ADD[7:4]
ADD[3:0]
RTO
E
N
AB
R
M
O
D
1
AB
R
M
O
D
0
ABRE
N
MSBFI
R
ST
DA
TA
INV
TXIN
V
RXINV
SW
A
P
LI
NEN
STOP
[1:0]
CL
KEN
CPOL
CPHA
LBCL
Res.
LBDI
E
LBDL
ADDM7
Res.
Res.
Res.
Res.
Reset value
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0
0
0 0 0 0
0 0 0
0x08
USART_CR3
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
WUF
IE
WUS
SCARCNT2:0
]
Res.
DEP
DE
M
DDRE
OVRDIS
ONEB
IT
CTS
IE
CTSE
RT
S
E
DMA
T
DMA
R
SCEN
NACK
HDSE
L
IRL
P
IRE
N
EI
E
Reset value
0 0 0 0 0 0
0 0
0
0
0 0 0 0 0 0 0 0 0
0
0
0
0x0C
USART_BRR
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
Re
s.
BRR[15:0]
Reset value
0 0
0
0
0 0 0 0 0 0 0 0 0
0
0
0
0x10
USART_GTPR
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
GT[7:0]
PSC[7:0]
Reset value
0 0
0
0
0 0 0 0 0 0 0 0 0
0
0
0
0x14
USART_RTOR
BLEN[7:0]
RTO[23:0]
Reset value
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0
0
0 0 0 0 0 0 0 0 0
0
0
0
0x18
USART_RQR
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
Res.
TXFRQ
RXFRQ
MMRQ
SBK
RQ
AB
RR
Q
Reset value
0 0
0
0
0