Chapter 4 Register Descriptions
© National Instruments Corporation 4-51 VXI-MXI User Manual
IRQ Acknowledge Registers
VXIbus Address: Base Address + 32 (hex) for IRQ1*
Base Address + 34 (hex) for IRQ2*
Base Address + 36 (hex) for IRQ3*
Base Address + 38 (hex) for IRQ4*
Base Address + 3A (hex) for IRQ5*
Base Address + 3C (hex) for IRQ6*
Base Address + 3E (hex) for IRQ7*
Attributes: Read Only
R
15 14 13 12 11 10 9
I15 I14 I13 I12 I11 I10 I9 I8
8
R
7 654321
I7 I6 I5 I4 I3 I2 I1 I0
0
These registers generate a VMEbus interrupt acknowledge cycle when they are read from a
MXIbus device.
Bit Mnemonic Description
15-0r I[15-0] Interrupt Acknowledge Status/ID
Reading from these registers generates an interrupt acknowledge
cycle on the VMEbus and returns the Status/ID value from the
interrupt acknowledge cycle. These registers can be used to handle
interrupts across the MXIbus. Each VMEbus IRQ line has a
separate interrupt acknowledge register, as shown above in the
VXIbus Address. The value returned when these registers are read
by a VMEbus device is hex FFFF.