XR17D154
xr
UNIVERSAL (3.3V AND 5V) PCI BUS QUAD UART
REV. 1.2.0
FIGURE 26. TRANSMIT DATA INTERRUPT AT TRIGGER LEVEL
START
BIT
STOP
BIT
DATA BITS (5-8)
TX Data
D0
D1
D2
D3
D4
D5
D6
D7
PARITY
BIT
NEXT
5 DATA BITS
DATA
START
BIT
6 DATA BITS
7 DATA BITS
Clear at
Above
Trigger Level
TX Interrupt at
Transmit Trigger Level
Set at Below
Trigger Level
BAUD RATE CLOCK of 16X or 8X
TXNOFIFO-1
FIGURE 27. RECEIVE DATA READY INTERRUPT AT TRIGGER LEVEL
START
BIT
STOP
BIT
DATA BITS (5-8)
RX Data Input
D0
D1
D2
D3
D4
D5
D6 D7
First byte that
reaches the
trigger level
PARITY
BIT
RX Data Ready Interrupt at
Receive Trigger Level
De-asserted at
below trigger level
Asserted at
above trigger
level
RXFIFO1
64