4.3.1
VXC Card
Interrupt Block Diagram
INT\
Level_trigger
INT_CHAN_0
INT_CHAN_1
initial_low
active_high
(to PCI slot)
The interrupt output signal of the VXC card,
INT\, is Level-Trigger and
Active_Low.
If INT\ generates a low_pulse, the VXC card will send an interrupt
signal to the PC only once. If INT\ is fixed in low_level, the VXC card will send
an interrupt signal to the PC continuously. Therefore,
INT_CHAN_0/1 must be
controlled as a pulse_type signal, which must normally be fixed in a
low_level state and should generate a high_pulse when sending an
interrupt signal to the PC.
The INT_CHAN_0/1 priority is the same as the above. If both signals are
active at the same time, then INT\ will activate only once. The interrupt service
routine must read the status of all interrupt channels for multi-channel interrupts.
If only one interrupt source is used, the interrupt service routine doesn’t need
to read the status of the interrupt source.
VXC Cards User’s Manual (Ver. 1.1, 06/09.2005, pmh-012-01) -----39
