XR16V554 Datasheet, PDF (17/45 Pages) Exar Corporation – 2.25V TO 3.6V QUAD UART WITH 16-BYTE FIFO

REV. 1.0.1
FIGURE 10. RECEIVER OPERATION IN FIFO
XR16V554/554D
2.25V TO 3.6V QUAD UART WITH 16-BYTE FIFO
16X Clock
16 bytes by 11-bit wide
FIFO
Receive Data
Byte and Errors
Receive Data Shift
Register (RSR)
R e c e iv e
Data FIFO
R e c e iv e
Data
Data Bit
V a lid a tio n
Receive Data Characters
E x a m p le
: - RX FIFO trigger level selected at 8 bytes
(See Note Below)
Data falls to
4
Asking for sending data when data falls below the flow
control trigger level to restart remote transmitter.
FIFO
Trigger=8
Data fills to
14
RHR Interrupt (ISR bit-2) programmed for
desired FIFO trigger level.
FIFO is Enabled by FCR bit-0=1
Asking for stopping data when data fills above the flow
control trigger level to suspend remote transmitter.
RXFIFO 1
17