Measurement Computing CIO-DAS801 - Manual (Page 12)

CIO-DAS801 User's Guide Installing the CIO-DAS801
12
Interrupt level
In order to take advantage of high speed transfers, you must provide the board with an interrupt that is not used
by other devices in your computer. Use the jumper block labeled IR (above the PC bus interface) to select an
interrupt level between 2 and 7, or to disable interrupts (X). By default, the board is shipped with no interrupt
level set (the jumper is in the 'X' position). Figure 5 shows the interrupt level set for IRQ 5.
IR
2 3 4 5 6 7 X
Figure 5. Interrupt level select jumper
Set the interrupt level jumper if your software requires it. The Universal Library and other programs which take
advantage of the REP-INSW high speed transfer capability of the board require an interrupt. If you set the
interrupt jumper, check your PC's current configuration for interrupt conflicts. Refer to the table below for
typical IRQ assignments.
IRQ assignments
Name Description Name Description
NMI Parity IRQ8 Real Time Clock (AT)
IRQ0 Timer IRQ9 Re-Directed to IRQ2 (AT)
IRQ1 Keyboard IRQ10 Unassigned
IRQ2 Reserved (XT)
INT 8-15 (AT)
IRQ11 Unassigned
IRQ3 COM OR SDLC IRQ12 Unassigned
IRQ4 COM OR SDLC IRQ13 80287 Numeric CO-P
IRQ5 Hard Disk (XT)
LPT (AT)
IRQ14 Hard Disk
IRQ6 Floppy Disk IRQ15 Unassigned
IRQ7 LPT Note: IRQ8-15 are AT only
Wait state jumper
Enable the wait state jumper if you have a computer with an I/O bus transfer rate which is too fast for the CIO-
DAS801, or if the board fails sporadically in random ways.
To enable the wait state, set the jumper labeled WS1 to the ON position. Enabling the wait state causes the
personal computer's bus transfer rate to slow down whenever the CIO-DAS801 is written to or read from. This
jumper is shown in Figure 6 configured for OFF (wait state is disabled).
ON OFF
WS1
Figure 6. Wait State jumper
The wait state generator on the CIO-DAS801 is only active when the CIO-DAS801 is being accessed. Your PC
will not be slowed down in general by using the wait state.