xr16m2551im48 Exar Corporation, xr16m2551im48 Datasheet - Page 16

• Manufacturer Part Number: xr16m2551im48
• Description: High Performance Low Voltage Duart With 16-byte Fifo And Powersave Feature
• Manufacturer: Exar Corporation

XR16M2551
HIGH PERFORMANCE LOW VOLTAGE DUART WITH 16-BYTE FIFO AND POWERSAVE FEATURE
Automatic RTS hardware flow control is used to prevent data overrun to the local receiver FIFO. The RTS#
output is used to request remote unit to suspend/resume data transmission. The auto RTS flow control
features is enabled to fit specific application requirement (see
•
•
If using the Auto RTS interrupt:
•
F
2.12
IGURE
Enable auto RTS flow control using EFR bit-6.
The auto RTS function must be started by asserting RTS# output pin (MCR bit-1 to HIGH after it is enabled).
Enable RTS interrupt through IER bit-6 (after setting EFR bit-4). The UART issues an interrupt when the
RTS# pin makes a transition from low to high: ISR bit-5 will be set to HIGH.
Receive Data
16X or 8X or 4X Clock
Byte and Errors
16 bytes by 11-bit wide
9. R
Auto RTS (Hardware) Flow Control
( DLD[5:4] )
ECEIVER
FIFO
O
PERATION IN
Receive Data Shift
Register (RSR)
Data FIFO
FIFO
Receive
Receive
Data
AND
A
UTO
Validation
Data falls to
Data fills to
Data Bit
Trigger=8
FIFO
14
RTS F
4
Example
16
: - RX FIFO trigger level selected at 8 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.
RHR Interrupt (ISR bit-2) programmed for
(See Note Below)
desired FIFO trigger level.
FIFO is Enabled by FCR bit-0=1
Figure
C
ONTROL
10):
M
ODE
Receive Data Characters
RXFIFO1
REV. 1.0.2