4. Jumper Settings
28
PC-686BX(NLX)-LV, PC-686BX(NLX)-LVV
I/O Addresses and Commands
The table below lists the I/O addresses used by COM2.
Table 4.3. I/O Addresses
I/O Address
DLAB
Read/Write
W
Transmitter hold register
THR
R
Receiver buffer register
RBR
1
W
Divisor latch register (LSB)
DLL
1
W
Divisor latch register (MSB)
DLM
0
W
Interrupt enable register
IER
02FAH
X
R
Interrupt ID register
IIR
02FBH
X
W
Line control register
LCR
02FCH
X
W
Modem control register
MCR
02FDH
X
R
Line status register
LSR
02FEH
X
R
Modem status register
MSR
02FFH
X
R/W
Scratch register
SCR
0
02F8H
02F9H
Register
RS-422/485 Terminating Resistance: JP3
Table 4.4. JP3: RS-422/485 Terminating Resistance
JP3
Terminating resistor
---
CTS for RS-422
RTS for RS-422
RXD for RS-422/485
TXD for RS-422/485
Function
No terminating resistor
(default)
Use terminating resistor
Use terminating resistor
Use terminating resistor
Use terminating resistor
2
1
7
8
2
1
7
8
2
1
7
8
2
1
7
8
2
1
7
8
Содержание PC-686BX(NLX)-LV
Страница 7: ...vi PC 686BX NLX LV PC 686BX NLX LVV ...
Страница 19: ...2 Specifications 12 PC 686BX NLX LV PC 686BX NLX LVV ...
Страница 45: ...5 CPU Board Resources 38 PC 686BX NLX LV PC 686BX NLX LVV ...
Страница 101: ...7 BIOS Setup 94 PC 686BX NLX LV PC 686BX NLX LVV ...