I/O Mapping; I/O Map - Serial Port 1; Table 8-1: I/O Map - Serial Port 1 - Addi-Data ADDICOM PA 7400 Series Technical Description

PA 7400
8.2

I/O mapping

Board PA 7400 requires an address range of 20 bytes within the I/O address
space of the PC.
They are allocated as follows:
•
8 bytes for serial port 1
•
8 bytes for serial port 2
•
4 bytes for the parallel port.

8.2.1 I/O map - serial port 1

Base-S1 +0 RECEIVER HOLDING REGISTER A
Base-S1 +1
Base-S1 +2 INTERRUPT IDENTIFICATION
Base-S1 +3
Base-S1 +4
Base-S1 +5
MODEM STATUS REGISTER A
Base-S1 +6
Base-S1 +7 INT2 INT1
D7
You will find the meaning of write and read data on addresses Base-S1 +0 to
Base-S1 +6
Address byte Base-S1 +7 (write):
DATA-DIR-1
RD-EN-1
DATA-DIR-2
RD-EN-2
Address byte Base-S1 +7 (read):
DATA-DIR-1
DATA-DIR-2
INT1
INT2
32

Table 8-1: I/O map - Serial port 1

I/O Read
INTERRUPT ENABLE REGISTER A
REGISTER A
LINE CONTROL REGISTER A
MODEM CONTROL REGISTER A
LINE STATUS REGISTER A
DATA-
DIR-2
D6 D1
Control bit of the transmitter for RS 485 serial port 1
See RS485 transmitter control
Control bit of the receiver for RS 485 serial port 1
See RS485 receiver control
Control bit of the transmitter for RS 485 serial port 2
RS485 transmitter control
Control bit of the receiver for RS 485 serial port 2
RS485 receiver control
Control bit of the transmitter for RS 485 serial port 1
Control bit of the transmitter for RS 485 serial port 2
Status bit for interrupt serial port 1
Status bit for interrupt serial port 2
Technical description
TRANSMIT HOLDING REGISTER A
DATA- RD-
DIR-1 EN-2
D0 D3
Chapter 8
I/O Write
RTSA DTRA
DATA- RD- DATA-
DIR-2 EN-1 DIR-1
D2 D1 D0