HP (Hewlett-Packard) PCI-9111DG/HR Manual De Usuario

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32 
 Operation Theorem 
users must check if another IRQ is also asserted, then clear current IRQ 
to allow the next IRQ occurring. 
The two IRQs are named as INT1 and INT2.  INT1 comes from AD EOC 
or the FIFO half-full flag.  INT2 comes from timer‘s pacer output or the 
external interrupt request.  The sources of INT1 and INT2 are selective by 
the Interrupt Control (ISC) Register. 
Because of dual interrupt system, for example, you can use FIFO half-full 
and external interrupt at the same time if your software ISR can 
distinguish these two events. 
 
4.2.4 
Interrupt Source Control 
There are two bits to control the IRQ sources of INT1 and INT2.  Refer to 
s ection 3.10 for the details of the bits.  In addition, the PCI controller itself 
can also control the using of the interrupt.  For manipulating the interrupt 
system more easily, ADLINK recommend you to use the function 
_9111_INT_Source_Control to control the IRQ source so that you can 
disable one or two of the IRQ sources. 
Note that even you disable all the two IRQ sources without change the 
initial condition of the PCI controller, the PCI BIOS still assigns an IRQ 
level to the PCI card and it will occupy the PC resource. It is not 
suggested to re-design the initial condition of the PCI card by users‘ own 
application software. If users want to disable the IRQ level, please use 
the ADLINK’s software utility to change the power on interrupt setting. 
 
4.3 
Extended Digital I/O Port 
There are 4 extended digital input (EDI) signals and 4 extended digital 
output (EDO) signals on CN3 connector. The 4 EDI signals are dedicated 
used as input signal, however the 4 EDO signals can be used as digital 
input (Mode 1), digital output (Mode 2) or channel number output (Mode 
3). 
For power on safety, the EDO channel is set to be input when power on 
initial. To modify the configuration of the usage of the signals, please use 
the “_9111_Set_EDO_Function” in the library. 
Note that w hen set the EDO function as channel number output (Mode 3), 
it presents the high nibble (4 MSBs) of the channel number no matter 
manual scan or auto scan mode.