XR17C158 Exar Corporation, XR17C158 Datasheet - Page 26

• Manufacturer Part Number: XR17C158
• Description: Eight-channel Pci-based (UART)
• Manufacturer: Exar Corporation

PRELIMINARY
The 8 sets of UART configuration registers are de-
coded using address lines A8 to A11 as show below.
Address lines A0 to A3 select the 16 registers in each
channel.
4.5 UART CHANNEL CONFIGURATION REGIS-
TERS AND ADDRESS DECODING.
F
IGURE
11. I
NTERNAL
L
OOP
B
ACK
Transmit Shift
Receive Shift
Register
Register
26
RTS#
DTR#
DSR#
CTS#
CD#
RI#
The first 8 registers are 16550 compatible with EXAR
enhanced feature registers located on the upper 8
addresses.
MCR bit-4=1
A11
0
0
0
0
1
1
1
1
OP1#
OP2#
VCC
VCC
VCC
A10
PCI BUS OCTAL UART
0
0
1
1
0
0
1
1
A9
0
1
0
1
0
1
0
1
RX [7:0]
TX [7:0]
RTS# [7:0]
CD# [7:0]
DTR# [7:0]
CTS# [7:0]
RI# [7:0]
DSR# [7:0]
A8
0
0
0
0
0
0
0
0
UART C
S
ELECTION
XR17C158
0
1
2
3
4
5
6
7
HANNEL
REV. 1.0.0