XR16C2852
xr
2.97V TO 5.5V DUAL UART WITH 128-BYTE FIFOS
REV. 2.1.1
14
FIGURE 9. RECEIVER OPERATION IN NON-FIFO MODE
FIGURE 10. RECEIVER OPERATION IN FIFO AND AUTO RTS FLOW CONTROL MODE
Receive Data Shift
Register (RSR)
Receive
Data Byte
and Errors
RHR Interrupt (ISR bit-2)
Receive Data
Holding Register
(RHR)
RXFIFO1
16X Clock
Receive Data Characters
Data Bit
Validation
Error
Tags in
LSR bits
4:2
Receive Data Shift
Register (RSR)
RXFIFO1
16X Clock
E
rro
rT
ags
(1
28-
sets)
E
rror
T
ags
in
LS
R
b
its
4:
2
128 bytes by 11-bit
wide FIFO
Receive Data Characters
FIFO Trigger=16
Example:
- RX FIFO trigger level selected at 16 bytes
(See Note Below)
Data fills to 24
Data falls to 8
Data Bit
Validation
Receive
Data FIFO
Receive
Data
Receive Data
Byte and Errors
RHR Interrupt (ISR bit-2) programmed for
desired FIFO trigger level.
FIFO is Enabled by FCR bit-0=1
RTS# de-asserts when data fills above the flow
control trigger level to suspend remote transmitter.
Enable by EFR bit-6=1, MCR bit-2.
RTS# re-asserts when data falls below the flow
control trigger level to restart remote transmitter.
Enable by EFR bit-6=1, MCR bit-2.