USART Operation: UART Mode
17-9
USART Peripheral Interface, UART Mode
17.2.4 USART Receive Enable
The receive enable bit, URXEx, enables or disables data reception on URXDx
as shown in Figure 17−5. Disabling the USART receiver stops the receive
operation following completion of any character currently being received or
immediately if no receive operation is active. The receive-data buffer,
UxRXBUF, contains the character moved from the RX shift register after the
character is received.
Figure 17−5. State Diagram of Receiver Enable
Idle State
(Receiver
Enabled)
Receive
Disable
Receiver
Collects
Character
URXEx = 0
No Valid Start Bit
Not Completed
URXEx = 1
URXEx = 0
URXEx = 1
Valid Start Bit
Handle Interrupt
Conditions
Character
Received
URXEx = 1
URXEx = 0
Note:
Re-Enabling the Receiver (Setting URXEx): UART Mode
When the receiver is disabled (URXEx = 0), re-enabling the receiver
(URXEx = 1) is asynchronous to any data stream that may be present on
URXDx at the time. Synchronization can be performed by testing for an idle
line condition before receiving a valid character (see URXWIE).
Summary of Contents for MSP430x4xx Family
Page 1: ...MSP430x4xx Family 2007 Mixed Signal Products User s Guide SLAU056G ...
Page 2: ......
Page 6: ...vi ...
Page 114: ...3 76 RISC 16 Bit CPU ...
Page 304: ...5 20 FLL Clock Module ...
Page 340: ...7 8 Supply Voltage Supervisor ...
Page 348: ...8 8 16 Bit Hardware Multiplier ...
Page 372: ...9 24 32 Bit Hardware Multiplier ...
Page 400: ...10 28 DMA Controller ...
Page 428: ...13 10 Basic Timer1 ...
Page 466: ...15 24 Timer_A ...
Page 522: ...17 30 USART Peripheral Interface UART Mode ...
Page 544: ...18 22 USART Peripheral Interface SPI Mode ...
Page 672: ...23 12 Comparator_A ...
Page 692: ...24 20 LCD Controller ...
Page 746: ...26 28 ADC12 ...