Chapter 3: Option Selection
Refer to the setup programs on the CD provided with the card. Also, refer to Figure 1-1, Block Diagram and
Figure 3-1, Option Selection Map when reading this section of the manual.
External Interrupts are accepted on the I/O connector pin 9 (bit C3) for each group. The Interrupt signal is
positive true. External Interrupts are enabled if the IEN0 (for Group 0) and IEN1 (for Group 1) jumper is
installed. Interrupts are directed to an available IRQ level by the system.
A means of enabling or disabling the 74LS245 input/output buffers under program control is provided at the
jumper position labeled TST/BEN. When the jumper is in the BEN (Buffer Enable) position, the I/O buffers
are always enabled. When the jumper is in the TST (Tristate) position, enabled/disabled state is controlled
by a control register. (See the programming section of this manual for a description.)
An LED, CR1, at the top left of the card to assist you in program development. Each time an interrupt is
generated, the LED will illuminate and remain ON until the interrupt is reset. If there is an immediate reset
of the interrupt, it is likely that the LED will not remain ON long enough to be observed.
Note
A jumper must be installed in either the TST or the BEN position for the card to function.
The foregoing are the only manual setups necessary to use either Input/Output selection. The change-of-
state Interrupt Disable/Enable is done via software by writing to a control register in each PPI as described
in Chapter 6, Programming.
Manual PCI-DIO-48(S)
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