Wait State; Installing The Cio-Dio24H - Measurement Computing CIO-DIO24H User Manual

CIO-DIO24H User's Guide
Name Description
NMI Parity
IRQ0 Timer
(AT)
IRQ1 Keyboard
IRQ2 Reserved (XT)
INT 8-15 (AT)
IRQ3 COM OR SDLC
IRQ4 COM OR SDLC
IRQ5 Hard Disk (XT)
LPT (AT)
IRQ6 Floppy Disk
IRQ7 LPT

Wait state

The CIO-DIO24H board has a wait state jumper which you can set to enable an on-board wait state generator
(see Figure 4). A wait state is an extra delay injected into the processor's clock via the bus. This delay slows
down the processor when the processor addresses the CIO-DIO24H board, so that signals from slow devices
(chips) will be accepted. The wait state generator is only active when the CIO-DIO24H is being accessed. Your
PC will not be slowed down in general by using the wait state.
The jumper is shown in
Because all PC expansion board busses are slowed to either 8 MHz or 10 MHz, the wait state will generally not
be required. If you experience sporadic errors from the 82C55 digital I/O chip (reset, port direction swaps), try
enabling the wait state generator.

Installing the CIO-DIO24H

After you configure the base address, you can install the CIO-DIO24H into your computer. Follow the steps
below.
Install the MCC DAQ software before you install your board
The driver needed to run your board is installed with the MCC DAQ software. Therefore, you need to install
the MCC DAQ software before you install your board. Refer to the Quick Start Guide for instructions on
installing the software.
Hardware interrupt assignments
Figure 4. Wait state jumper
Figure 4 is configured for
Name Description
IRQ8 Real Time Clock (AT)
IRQ9 Re-directed to IRQ2
IRQ10 Unassigned
IRQ11 Unassigned
IRQ12 Unassigned
IRQ13 80287 MUNERIC CO-P
IRQ14 Hard Disk
IRQ15 Not assigned
O
O F
N F
WAIT
STATE
(wait state is disabled).
OFF
12
Installing the CIO-DIO24H