Receiver Buffer Register (Rbr); Transmitter Holding Register (Thr); Interrupt Enable Register (Ier) - Korenix JetBox 8180 User Manual

DLAB Port Address
0 Base + 0
0 Base + 1
X Base + 2
X Base + 3
X Base + 4
X Base + 5
X Base + 6
X Base + 7
1 Base + 0
1 Base + 1

6-2-1 Receiver Buffer Register (RBR)

Bit 0-7: Received data byte (Read Only)

6-2-2 Transmitter Holding Register (THR)

Bit 0-7: Transmitter holding data byte (Write Only)

6-2-3 Interrupt Enable Register (IER)

Bit 0: Enable Received Data Available Interrupt (ERBFI)
Bit 1: Enable Transmitter Holding Empty Interrupt (ETBEI)
Bit 2: Enable Receiver Line Status Interrupt (ELSI)
Bit 3: Enable MODEM Status Interrupt (EDSSI)
Bit 4: Must be 0
Bit 5: Must be 0
Register
Receiver buffer (read)
Transmitter holding register
(write)
Interrupt enable
Interrupt identification (read only)
Line control
MODEM control
Line status
MODEM status
Scratched register
Divisor latch (least significant
byte)
Divisor latch (most significant
byte)
Korenix | Technical Reference 59