xr20m1280 Exar Corporation, xr20m1280 Datasheet - Page 19

• Manufacturer Part Number: xr20m1280
• Description: I2c/spi Uart With 128-byte Fifo And Integrated Level Shifters
• Manufacturer: Exar Corporation

REV. P1.1.1
F
F
IGURE
IGURE
Receive Data
16X or 8X or 4X Clock
Byte and Errors
128 bytes by 11-bit wide
16. R
17. R
( DLD[5:4] )
ECEIVER
ECEIVER
FIFO
16X or 8X or 4X Clock
( DLD[5:4] )
and Errors
Data Byte
Receive
O
O
PERATION IN NON
PERATION IN
Receive Data Shift
Register (RSR)
I2C/SPI UART WITH 128-BYTE FIFO AND INTEGRATED LEVEL SHIFTERS
Data FIFO
Receive
Receive
LSR bits
Tags in
FIFO
Data
Error
4:2
-FIFO M
Receive Data Shift
AND
Register (RSR)
Holding Register
Receive Data
A
Validation
Data falls to
Trigger=16
Data fills to
UTO
Data Bit
ODE
(RHR)
PRELIMINARY
FIFO
56
Example
8
RTS F
19
: - RX FIFO trigger level selected at 16 bytes
LOW
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.
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.
Validation
RHR Interrupt (ISR bit-2) programmed for
(See Note Below)
desired FIFO trigger level.
FIFO is Enabled by FCR bit-0=1
Data Bit
C
ONTROL
RHR Interrupt (ISR bit-2)
M
ODE
Receive Data Characters
Receive Data Characters
RXFIFO1
XR20M1280
RXFIFO1