Technical information

OPTO DIO Reference Opto DIO48
Interrupt Selection._________________
The Opto DIO48 card can produce interrupts from low to
high transitions on three signal lines, Watch Dog timeout, Port
C2 input bit 0 and Port C2 input bit 3.
The IRQ must be ENABLED in software AND the IRQ
jumper must both be set before any IRQ requests are generated.
Thus IRQs can be enabled under program control to suit the
changing needs of the application. The position of the jumper
MUST match the IRQ level set in the software.
The IRQ enable bits in the watch dog register selects
which Opto DIO48 signal generates the interrupt, the IRQ
jumper block selects which PC interrupt line is asserted, and so
which software interrupt service routine is called. Write your
IRQ service routine to patch the appropriate software interrupt.
Watch Dog Selection.___________________
Two sets of jumpers, at the lower left side of the card, are
used to control the Watch Dog output function, this determines
which signals are used to generate an interrupt or reset signal or
are to be patched through to the watch dog output. The watch
dog enable register is an 8 bit read write register, see Chapter 1.
Figure 2-8. Watchdog Output Select.________________________________
FACTORY SET___________
RESLO BUS Approx 1 microsec LOW pulse on timeout
RESHI BUS Approx 1 microsec HIGH pulse on timeout
RESHI OUT Approx 1 microsec HIGH pulse on timeout
RESLO OUT Approx 1 microsec LOW pulse on timeout
GOODLO OUT LOW level= not timed out, low 50 milli sec
GOODHI OUT HIGH level = not timed out, hi 50 milli sec
Page 22 Chapter 2