CC1110Fx / CC1111Fx
13.14.6 USART DMA Triggers
Refer to Table 51 on page 108 for an overview
of the DMA triggers.
There are two DMA triggers associated with
each USART (URX0, UTX0, URX1, and
UTX1). The DMA triggers are activated by RX
complete and TX complete events i.e. the
same events that might generate USART
interrupt requests. A DMA channel can be
configured using a USART Receive/transmit
buffer, UxDBUF, as source or destination
address.
13.14.7 USART Registers
The registers for the USART are described in
this section. For each USART there are five
registers consisting of the following (x refers to
USART number i.e. 0 or 1):
•
•
•
•
UxCSRUSART x Control and Status
UxUCRUSART x UART Control
UxGCRUSART x Generic Control
UxDBUF USART x Receive/Transmit
Data Buffer
Note: For systems requiring setting
UxGDR.CPHA=1, the DMA can not be
used.
•
UxBAUDUSART x Baud Rate Control
U0CSR (0x86) – USART 0 Control and Status
Bit
Name
Reset
R/W
Description
7
MODE
0
R/W
USART 0 mode select
0
1
SPI mode
UART mode
6
5
4
RE
0
0
0
R/W
R/W
R/W0
UART 0 receiver enable
0
1
Receiver disabled
Receiver enabled
SLAVE
FE
SPI 0 master or slave mode select
0
1
SPI master
SPI slave
UART 0 framing error status
0
1
No framing error detected
Byte received with incorrect stop bit level
Note: TCON.URX0IF and U0CSR.RX_BYTEbit will be asserted when
the first stop bit is checked OK, meaning that if two stop bits are sent and
the second stop bit is not OK, this bit is asserted 1 bit duration later than
the 2 other above mentioned bits.
3
2
1
0
ERR
0
0
0
0
R/W0
R/W0
R/W0
R
UART 0 parity error status
0
1
No parity error detected
Byte received with parity error
RX_BYTE
TX_BYTE
ACTIVE
Receive byte status
0
1
No byte received
Received byte ready
Transmit byte status
0
1
Byte not transmitted
Last byte written to Data Buffer register transmitted
USART 0 transmit/receive active status
0
1
USART 0 idle
USART 0 busy in transmit or receive mode
SWRS033E
Page 157 of 239