Chapter 4
Nonvolatile Configuration
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National Instruments Corporation
4-7
As part of the hardware capabilities on the GPIB-VXI/C, there are three
VXI programmable interrupt handlers. They can be assigned dynamically
by the RM or statically according to the contents of the nonvolatile
memory.
A24 Assign Base
This entry determines the A24 address where the Resource Manager will
begin allocating A24 address space for VXI devices. You can use this
field to avoid conflicts with VME devices that use A24 address space.
In addition, you can guarantee that a bus master can access the range of
address space that a particular device is configured to occupy. The VXIbus
specification requires A24 bus masters to see addresses from 200000h to
DFFFFFh.
A32 Assign Base
This entry determines the A32 address where the Resource Manager will
begin allocating A32 address space for VXI devices. You can use this
field to avoid conflicts with VME devices that use A32 address space.
In addition, you can guarantee that a bus master can access the range of
address space that a particular device is configured to occupy. The VXIbus
specification requires A32 bus masters to see addresses from 20000000h to
DFFFFFFFh.
DC Starting Logical Address
This parameter specifies the first logical address the Resource Manager
should use to begin assigning Dynamic Configuration (DC) devices.
DC devices will be assigned the next higher unassigned logical address.
BNO
This parameter specifies whether the Resource Manager should send
Identify Commander
and
Begin Normal Operation
in a DC system.
DC systems cannot specify an intended hierarchy and must be configured
externally—normally through the local commands
DCGrantDev
and
DCBNOsend
. The most common configuration, however, is to assign all DC
devices to Logical Address 0 (the RM). If BNO is specified to be sent, all
DC devices are assigned to Logical Address 0 and the
Identify Commander
and
Begin Normal Operation
commands are sent. If BNO is specified
not
to be sent, no devices—neither SC nor DC—will be sent the
Begin Normal
Operation
command.
DCBNOsend
must be sent to the local command set to
initiate normal operation after the hierarchy is established.
