Contec SPI-8550-LLVAS, User Manual

Page: 45 / 78

4. Jumper Setting
38
SPI-8550-LLVAS
I/O addresses and instructions
The table below lists I/O addresses for use as COM2.
Table 4.7. I/O addresses
I/O address DLAB Read/Write Register
W Transmitter holding Register THR
0
R Receiver buffer Register RBR
02F8H
1 W Divisor latch Register (LSB) DLL
1 W Divisor latch Register (MSB) DLM
02F9H
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
RS-422/485 Terminator: JP7
Table 4.8. RS-422/485 Terminator
JP7 Function
No terminating resister (Default)
terminating resister provided
terminating resister provided
terminating resister provided
terminating resister provided
Terminator
-
CTS for RS-422
RTS for RS-422
RXD for RS-422/485
TXD for RS-422/485
2
4
6
8 1
3
5
7
2
4
6
8
1
3
5
7
2
4
6
8 1
3
5
7
2
4
6
8 1
3
5
7
2
4
6
8
1
3
5
7