Functional Description
MEN Mikro Elektronik GmbH
69
20A014-00 E2 – 2007-08-16
2.16.11
VMEbus Interrupter
The board has one interrupter. It can generate an interrupt on all seven levels, but
only one at a time. The interrupt level is selected in the
INTR – VME Interrupter
Control Register (
0x0000
) (read/write)
. The associated interrupt status ID, which
is provided to the interrupt handler during the IACK cycle, is stored in the
INTID –
VME Interrupt STATUS/ID Register (
0x0004
) (read/write)
. The interrupt request
is auto cleared after an IACK cycle (ROAK).
INTR – VME Interrupter Control Register (
0x0000
) (read/write)
This register controls the internal interrupter. Interrupt levels from 1 to 7 can be set.
The interrupt is generated only when the
INTEN
bit is set.
INTEN
should be set after the
ILx
bits are set to avoid glitches on the IRQ lines.
INTEN
is automatically cleared during the acknowledge cycle and the request is
removed (ROAK). The
ILx
bits, however, remain set until they are overwritten.
Check the
INTEN
bit to verify that the interrupt has been acknowledged.
INTID – VME Interrupt STATUS/ID Register (
0x0004
) (read/write)
In this Register, the STATUS/ID of the internal interrupter is set.
7..4
3
2
1
0
-
INTEN
IL2
IL1
IL0
INTEN
Interrupter enable
0 =
1 =
Interrupt disabled (default)
Enable interrupt at level specified through
ILx
The interrupt level is set in binary code (e. g.
ILx
=011 is IRQ3).
Default:
0x0
ILx
Interrupter request level
The level is set by a binary value of a 3-to-7 demultiplexer (e.g.
IL[2:0]=011 is IRQ3).
Default:
0x0
7..0
INT_ID
INT_ID
The STATUS/ID of the interrupt that the external handler reads during
the IACK cycle.
Default:
0x00