xr17v258 Exar Corporation, xr17v258 Datasheet - Page 53

• Manufacturer Part Number: xr17v258
• Description: 66mhz Pci Bus Octal Uart With Power Management Support
• Manufacturer: Exar Corporation

xr
REV. 1.0.0
FCTR[4]: Infrared RX Input Logic Select
•
•
FCTR [3:0] - Auto RTS/DTR Flow Control Hysteresis Select
These bits select the auto RTS/DTR flow control hysteresis and only valid when TX and RX Trigger Table-D is
selected (FCTR bit [7:6] 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 hardware flow control.
below shows the 16 selectable hysteresis levels.
Enhanced features are enabled or disabled using this register. Bits [3:0] provide single or dual consecutive
character software flow control selection (see
are selected, the double 8-bit words are concatenated into two sequential characters. Caution: note that
whenever changing the TX or RX flow control bits, always reset all bits back to logic 0 (disable) before
programming a new setting.
EFR[7]: Auto CTS Flow Control Enable
Automatic CTS or DSR Flow Control.
•
•
5.14
Logic 0 = Select RX input as active HIGH encoded IrDA data, normal, (default).
Logic 1 = Select RX input as active LOW encoded IrDA data, inverted.
Logic 0 = Automatic CTS/DSR flow control is disabled (default).
Logic 1 = Enable Automatic CTS/DSR flow control. Transmission stops when CTS/DSR# pin de-asserts
(HIGH). Transmission resumes when CTS/DSR# pin is asserted (LOW). The selection for CTS# or DSR# is
through MCR bit [2].
Enhanced Feature Register (EFR) - Read/Write
FCTR B
T
ABLE
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
IT
[3]
19: 16 S
FCTR B
ELECTABLE
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
66MHZ PCI BUS OCTAL UART WITH POWER MANAGEMENT SUPPORT
IT
[2]
H
YSTERESIS
FCTR B
Table 20
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
IT
L
[1]
EVELS
53
). When the Xon1 and Xon2 and Xoff1 and Xoff2 modes
W
FCTR B
HEN
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
T
RIGGER
IT
[0]
T
ABLE
RTS/DTR H
-D
(
CHARACTERS
IS
+/- 16
+/- 24
+/- 32
+/- 12
+/- 20
+/- 28
+/- 36
+/- 40
+/- 44
+/- 48
+/- 52
S
+/- 4
+/- 6
+/- 8
+/- 8
ELECTED
0
YSTERESIS
)
XR17V258
Table 19