Interrupt Control; System Architecture - NuDAQ PCI- 9113A User Manual

2's Complement Coding:
Bipolar 10V
Voltage = ( AD_Data * 20 ) / ( 4096 * gain )
Bipolar 5V
Voltage = ( AD_Data * 10 ) / ( 4096 * gain )
Unipolar +10V:
Voltage = ( AD_Data * 10 ) / ( 4096 * gain ) + (5 / gain)
where the gain is 1,10,100.
Note: For 2's complement coding, user should shift the MSB of
AD_data to be the sign bit of the corresponding signed variable,
and over the variable by the shift amount to get the correct value.
5.2

Interrupt Control

5.2.1

System Architecture

The PCI-9113A'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 5.2.1 shows the interrupt
system.
INT #A
32 Operation Theorem
:
:
INT1
PCI
Controller
INT2
Clear IRQ
IRQ
Flip-Flo
ps
AD EOC
INT1
FIFO
MUX
Half-full
Timer Pacer