Xycom XVME-678 Manual page 102

Chapter
4 -
Programming
4.9 SYSTEM RESOURCE FUNCTIONS
System resource functions are provided by a switch. The switch controls enabling of the lACK daisy chain
driver, BERR timeout, the arbiter, and the SYSCLK driver. The bus error timeout assertion occurs 16
usec after the data strobes. The switch position can be read back in Control Register 6 (3FH).
The module is reset by VME SYSRESET* or the Vcc going out of tolerance. The module will assert
VME SYSRESET* in one of two conditions:
• Vcc is out of tolerance
and
switch SW1, position 1 is closed.
Or
• The toggle switch is toggled down
and
switch SW1, position 2 is closed.
See Figure 4-14 for a block diagram of the reset structure.
8-POSITION SWITCH
DC+5V
Monitor
RESET*
rcx:n.E
IL.--_--i
SWITCH TRESET*
4-30
VMESYSRESET*
-
~
Local CPU RESET*
L . - -_ _
----I~
Figure 4-14. Reset Structure