User manual

23 Chapter 2
Figure 2.19: Standard or Enhanced Mode selection for PCL-846A/B
Figure 2.20: Standard or Enhanced Mode selection for PCL-849A/B/+
Standard Mode
In this mode each of the four ports can be setup as the address or the IRQ
channel individually.
Enhanced Mode
In this mode all four ports share the same IRQ and continue to use the
cards designated IRQ address. This mode also utilizes an interrupt status
register designed to indicate which serial port has generated an interrupt.
This mode speeds up interrupt processing resulting in a greater through-
put for each multi-port card.
Port Base Address
13F8
22F8
33E8
42E8