CC2430
Peripherals : USART
13.14.5 USART flushing
The current operation can be aborted by
setting the UxUCR.FLUSH register bit. This
event will stop the current operation and clear
all data buffers. It should be noted that setting
the flush bit in the middle of a TX/RX bit, the
flushing will not take place until this bit has
ended (buffers will be cleared immediately but
timer keeping knowledge of bit duration will
not). Thus using the flush bit should either be
aligned with USART interrupts or use a wait
time of one bit duration at current baud rate
before updated data or configuration can be
received by the USART.
13.14.6 USART Interrupts
Each USART has two interrupts. These are
the RX complete interrupt (URXx) and the TX
complete interrupt (UTXx).
Interrupt enables:
•
•
•
•
USART0 RX : IEN0.URX0IE
USART1 RX : IEN0.URX1IE
USART0 TX : IEN2.UTX0IE
USART1 TX : IEN2.UTX1IE
The USART interrupt enable bits are found in
the IEN0 and IEN2 registers. The interrupt
flags are located in the TCON and IRCON2
registers. Refer to section 11.5 on page 49 for
details of these registers. The interrupt
enables and flags are summarized below.
Interrupt flags:
•
•
•
•
USART0 RX : TCON.URX0IF
USART1 RX : TCON.URX1IF
USART0 TX : IRCON2.UTX0IF
USART1 TX : IRCON2.UTX1IF
13.14.7 USART DMA Triggers
There are two DMA triggers associated with
each USART. The DMA triggers are activated
by RX complete and TX complete events i.e.
the same events as the USART interrupt
requests. A DMA channel can be configured
using
a
USART Receive/transmit buffer,
UxDBUF, as source or destination address.
Refer to Table 41 on page 94 for an overview
of the DMA triggers.
13.14.8 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
• UxBAUDUSART x Baud Rate Control
CC2430 Data Sheet (rev. 2.1) SWRS036F
Page 146 of 211
TAOS [ TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS ]
