Measurement Computing CIO-CTR05 - Manual (Page 11)

CIO-CTR05 User's Guide Installing the CIO-CTR05
11
Interrupt level select jumper
Use the Interrupt Level Select jumper located above the PC bus interface (gold pins) to set the IRQ number you
want the interrupt pulse on.
This jumper is set by default with no interrupt level set ("X" position). Interrupts are hardware initiated
software routines and are described in the section on programming.
2 3 4 5 6 7 X
IR1
Figure 2. Interrupt Level Select jumper
Pin 1 (IR INPUT) of the 37-pin connector is an input jumper which maps the interrupt directly onto the PC bus.
The signal to the bus is buffered. The buffer is enabled by a TTL low level on Pin 2 (IR ENABLE).
Hardware interrupts assigned by the PC may be available; refer to the following table. Note that IRQ8 to IRQ15
are AT only.
Name Description Name Description
NMI Parity IRQ8 Real Time Clock (AT)
IRQ0 (AT) Timer IRQ9 Re-Directed To IRQ2
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 (AT) LPT (AT) IRQ14 Hard Disk
IRQ6 Floppy Disk IRQ15 Unassigned
IRQ7 LPT
Wait state jumper
The CIO-CTR05 board has a wait state jumper which you can set to enable an on-board wait state generator. 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-CTR05 board so that signals from slow devices (chips) will be valid.
The jumper is shown in Figure 3 configured for OFF (wait state is disabled).
O
N
O
F
F
WAIT
STATE
Figure 3. Wait State jumper
The wait state generator on the CIO-CTR05 is only active when the CIO-CTR05 is being accessed. Your PC
will not be slowed down in general by using the wait state.