Computer Hardware User Manual

Chapter 3: Option Selection

Refer to the setup programs on the CD provided with the card. Also, refer to the Block Diagram and the

Option Selection Map when reading this section of the manual.

Buffer Mode Jumper

A means of enabling or disabling (tristating) the 74ABT245B 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 Chapter 6, Programming for a description.

Note

A jumper must be installed in EITHER the TST or the BEN position for the card to function.

Interrupt Mode Jumpers

Place the Interrupt Select 0 jumper in the INT position to select the Digital I/O interrupt.

Place the Interrupt Select 0 jumper in the EXT position to select the External Input interrupt.

Install the IRQD jumper to enable the Digital I/O or External Input interrupts.

Install the IRQT jumper to enable the Timer generated interrupt.

The foregoing are the only manual setups necessary to use these cards. Input/Output selection is done

via software by writing to a control register in the PPI as described in the Programming chapter of this

manual.

Optionally, the card may have been modified at the factory to convert the pull up resistors to pull down

resistors. The model number would then be similar to D S04 or H S04.

Manual PCI-DIO-24DH