Interrupt Sharing

An interrupt sharing circuit allows a port on the DS-102 to share an
interrupt with the other port on the board or with another Quatech
adapter supporting sharable interrupts. When interrupt sharing is used,
the software must query each port attached to a given IRQ level when an
interrupt for that IRQ is received by the computer.
Use of this feature is beyond the capabilities of most commercial
applications. If the software to be used with the DS-102 is not specially
written to take advantage of interrupt sharing, then ensure that each port
being used is connected to a different IRQ level.
Interrupt sharing is controlled by jumper J2 as described by Figure
8 and Figure 9. To maintain 100% ISA bus compatibility, these jumpers
should be set to the dedicated interrupt level positions.
Interrupt sharing enabled
J3: 1-2 and 4-5
Dedicated interrupt level (default)
J3: 2-3 and 5-6
Serial 2
Interrupt sharing enabled
J2: 1-2 and 4-5
Dedicated interrupt level (default)
J2: 2-3 and 5-6
Serial 1
INTERRUPT OPERATION
CONNECTION
CHANNEL
Figure 8 --- Interrupt sharing modes
13
2
4 65
Sharing enabled
13
2
4 65
Dedicated interrupt
(non-sharing)
Serial 1 uses J2Serial 2 uses J3
Figure 9 --- J2, J3 settings
Quatech
DS-102 User's Manual