ADLINK Technology NuDAQ PCI-9114DG, Руководство пользователя

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Operation Theorem
4.2 Interrupt Control
4.2.1 System Architecture
The PCI-9114‘s interrupt system is a powerful and flexible system that is
suitable for A/D data acquisition and many applications. The system is
a
Dual Interrupt System . The dual interrupt means the hardware can
generate two interrupt request signals in the same time and the
software can service these two request signals by ISR. Note that the
dual interrupt does not mean the card occupies two IRQ levels.
The two interrupt request signals (INT1 and INT2) come from digital
signals or the timer / counter output. An interrupt source multiplexer
(MUX) is used to select the IRQ sources. Fig 4.2.1 shows the interrupt
system.
Figure 4.2.1 Dual Interrupt System of PCI-9114
4.2.2 IRQ Level Setting
There is only one IRQ level used by this card, although it is a dual
interrupt system. This card uses INT #A interrupt request signal to PCI
bus. The motherboard circuits will transfer INT #A to one of the AT bus
IRQ levels. The IRQ level is set by the PCI plug and play BIOS. This
value is saved in the PCI controller. It is not necessary for users to set
the IRQ level.
4.2.3 Dual Interrupt System
The PCI controller of PCI-9114 can receive two hardware IRQ sources.
However, a PCI controller can generate only one IRQ to PCI bus, the two IRQ
sources should be distinguished by ISR of the application software if the two
IRQ are all used.
PCI
Controller
INT #A
IRQ
Flip-Flops
INT1
Clear IRQ#1, #2
INT1
MUX
AD EOC
Timer Pacer
INT2
FIFO
Half-full