USART Operation: UART Mode
17-20
USART Peripheral Interface, UART Mode
Receive-Start Edge Detect Conditions
When URXSE = 1, glitch suppression prevents the USART from being
accidentally started. Any low-level on URXDx shorter than the deglitch time t
τ
(approximately 300 ns) will be ignored by the USART and no interrupt request
will be generated as shown in Figure 17−12. See the device-specific data
sheet for parameters.
Figure 17−12. Glitch Suppression, USART Receive Not Started
URXDx
URXS
t
τ
When a glitch is longer than
t
τ,
or a valid start bit occurs on URXDx, the USART
receive operation is started and a majority vote is taken as shown in
Figure 17−13. If the majority vote fails to detect a start bit the USART halts
character reception.
If character reception is halted, an active BRCLK is not necessary. A time-out
period longer than the character receive duration can be used by software to
indicate that a character was not received in the expected time and the
software can disable BRCLK.
Figure 17−13. Glitch Suppression, USART Activated
URXDx
URXS
t
τ
Majority Vote Taken
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 ...