Contec SPI-8450-LLVA User Manual
CHAPTER 3 – Jumper setting
28
SPI-8450-LLVA
I/O addresses and instructions
The table below lists I/O addresses for use as COM2.
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