Multiprocessor Configuration
30 – Configuration
VL-486-4 Reference Manual
Multiprocessor Configuration
The VL-486-4 CPU card supports multiple master operation for systems requiring additional
processing capability or for “smart I/O” operations. In a multiple master system, one CPU must
be configured as a permanent master and other CPUs are configured as temporary masters. In
this scheme, a bus arbiter plugged into Slot X is used to arbitrate access to the bus. A special
dualmaster mode is available for two CPUs to work together without a bus arbiter. In this
configuration, one CPU should be jumpered as a permanent master and the other CPU should be
jumpered as a dualmaster.
M
ULTIPROCESSOR
J
UMPER
C
ONFIGURATION
Jumper blocks V2 and V8 are used to select the bus mastering mode.
Table 11: Multiprocessor Configuration Jumpers
Jumper
Block
Description
As
Shipped
V2[3-4]
Multiprocessor Configuration
In
— Dual master mode. Uses BUSAK* (P41) for bus arbitration.
Out
— Permanent or temporary master mode.
Out
V2[5-6]
Multiprocessor Configuration
In
— Dual master mode. Uses BUSRQ* (P42) for bus arbitration.
Out
— Permanent or temporary master mode.
Out
V8[1-2]
CPU response to SYSRESET*
In
— CPU resets whenever STD Bus SYSRESET* (P47) goes low
Out
— CPU ignores activity on STD Bus SYSRESET* (P47)
Out
V8[3-4]
Push-button Reset / Bus Interconnect
In
— Connects STD Bus PBRESET* (P48) to CPU reset circuits
Out
— CPU ignores activity on, and does not drive STD Bus PBRESET* (P48)
In
V8[7-8]
Permanent / Temporary Master Selection
In
— Permanent Master Mode (V8[1-2] must be out, RP13 – RP20 must be
in)
Out
— Temporary Master Mode (RP13 – RP20 must be out)
In
