C-2
Register Maps
Table C-1 summarizes the PIO-32 Series register maps.
Table C-2 lists the register map for the PIO-32I/O board; Table C-3 lists
the register map for the PIO-32IN board; and Table C-4 lists the register
map for the PIO-32OUT board.
Notes:
In each table, the abbreviation BA is for the Base Address.
For input port bits:
0 = no current through optoisolator,
1 = current > 1.25mA (voltage > 3.5V)
For output port bits:
0 = relay is not activated (open)
1 = relay is activated (closed
Table C-1. PIO-32 Series Register Map Summary
Base
8255 Port
PIO-32IN
PIO-32OUT
PIO-32I/O
+0h
Port A
Read
Readback/Write
Read
+1h
Port B
Read
Readback/Write
Read
+2h
Port C (not used)
N/A
N/A
N/A
+3h
Control Register (fixed)
N/A
N/A
N/A
+4h
Port A
Read
Readback/Write
Readback/Write
+5h
Port B
Read
Readback/Write
Readback/Write
+6h
Port C (not used)
N/A
N/A
N/A
+7h
Control Register (fixed)
N/A
N/A
N/A
