XR16L784 Exar Corporation, XR16L784 Datasheet - Page 29

• Manufacturer Part Number: XR16L784
• Description: High Performance 5V And 3.3V Quad Uart
• Manufacturer: Exar Corporation

This is a 8-bit general purpose register for the user to
store temporary data. The content of this register is
preserved during sleep mode but becomes 0xFF (de-
fault) after a reset or a power off-on cycle.
This register controls the UART enhanced functions
that are not available on ST16C554 or ST16C654.
FCTR [3:0] - Auto RTS/DTR Flow Control Hystere-
sis Select
4.11.9 SCRATCH PAD REGISTER (SPR)
4.11.10 FEATURE CONTROL REGISTER (FCTR)
T
ABLE
T
ABLE
12: A
FCTR B
13: 16 S
UTO
MSR[7]
3
0
0
0
0
0
0
RS485 H
0
0
0
0
0
9
0
0
1
1
1
1
1
1
1
1
IT
-
ELECTABLE
FCTR B
MSR[6]
ALF
2
0
0
0
0
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
-
DUPLEX
IT
H
-
YSTERESIS
MSR[5]
FCTR B
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
D
1
0
0
1
1
0
0
IRECTION
IT
-
L
MSR[4]
EVELS
29
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
FCTR B
These bits select the auto RTS/DTR flow control hys-
teresis and only valid when TX and RX Trigger Table-
D is selected (FCTR bit-6 and 7 are set to logic 1).
The RTS/DTR hysteresis is referenced to the RX
FIFO trigger level. After reset, these bits are set to
logic 0 selecting the next FIFO trigger level for hard-
ware flow control.
able hysteresis levels.
HIGH PERFORMANCE 5V AND 3.3V QUAD UART
C
ONTROL
0
0
1
0
1
0
1
W
HEN
IT
D
-
ELAY IN
T
D
RIGGER
ELAY FROM
RTS/DTR H
D
ATA
10
12
13
14
15
(
11
Table 13
CHARACTERS
0
1
2
3
4
5
6
7
8
9
T
ABLE
B
+/- 16
+/- 4
+/- 6
+/- 8
+/- 8
IT
T
0
(
S
RANSMIT
YSTERESIS
-D
) T
below shows the 16 select-
IME
IS
)
S
ELECTED
-
TO
-R
ECEIVE
XR16L784
REV. 1.0.1