XR16V2550 Datasheet, PDF (14/48 Pages) Exar Corporation – HIGH PERFORMANCE DUART WITH 16-BYTE FIFO

XR16V2550
PRELIMINARY
HIGH PERFORMANCE DUART WITH 16-BYTE FIFO
FIGURE 8. RECEIVER OPERATION IN NON-FIFO MODE
REV. P1.0.0
16X or 8X or 4X Clock
( DLD[5:4] )
Receive Data Shift
Register (RSR)
Data Bit
V alida tion
Receive Data Characters
R e ce iv e
Data Byte
and Errors
Error
Tags in
LSR bits
4:2
Receive Data
Holding Register
(R H R )
RHR Interrupt (ISR bit-2)
R XF IFO 1
FIGURE 9. RECEIVER OPERATION IN FIFO AND AUTO RTS FLOW CONTROL MODE
16X or 8X or 4X Clock
( DLD[5:4] )
16 bytes by 11-bit wide
FIFO
Receive Data
Byte and Errors
Receive Data Shift
Register (RSR)
Receive
Data FIFO
Receive
Data
Data Bit
Validation
Receive Data Characters
Example
: - RX FIFO trigger level selected at 8 bytes
(See Note Below)
Data falls to
4
RTS# re-asserts when data falls below the flow
control trigger level to restart remote transmitter.
Enable by EFR bit-6=1, MCR bit-1.
FIFO
Trigger=8
RHR Interrupt (ISR bit-2) programmed for
desired FIFO trigger level.
FIFO is Enabled by FCR bit-0=1
Data fills to
14
RTS# de-asserts when data fills above the flow
control trigger level to suspend remote transmitter.
Enable by EFR bit-6=1, MCR bit-1.
RXFIFO1
14