Xycom XVME-678 Manual page 122

Chapter 5 - XVME BIOS Functions
5.5 VMEbus MASTER FUNCTIONS
This category of functions allows programs to access the software configuration of the module's VMEbus
Master interface. Functions are provided to read and modify the Master interface configuration and
request VMEbus ownership. For more information on the master interface, refer to Section 4.8.
5.5.1 Get VMEbus Master Configuration
The information returned from this function provides programs with the current state of the VMEbus
master interface, address modifier codes used for master cycles, the VMEbus request level used, and the
VMEbus requester configuration.
Int 15h
Function AFH
Call With:
Returns:
Subfunction 30H
AH
=
AFH
AL
=
30H
If error: Carry Flag Set
If successful:
AH
=
Error Code
DJ
=
"XY"
Carry Flag Clear
AH
=
0
DJ
=
"XY"
BX
=
Current VMEbus master configuration
5-18
Bit 0 0
1
Bit 2 0
1
Bit 3-4 00
01
10
11
Bit 5 0
1
- VMEbus master interface disabled
- VMEbus master interface enabled
- VMEbus master accesses non-privileged
- VMEbus master accesses supervisory
VMEbus request level 3
VMEbus request level 2
VMEbus request level 1
VMEbus request level 0
- Release VMEbus when done
- Release VMEbus on request