user manual

Operating Instructions
3-2
3
RESET Switch S2
The recessed front panel RESET switch resets all onboard devices,
and drives SYSRESET* if the board is system controller. The RESET
switch may be disabled by software.
The VMEchip2 includes both a global and a local reset driver. When
the chip operates as the VMEbus system controller, the reset driver
provides a global system reset by asserting the VMEbus signal
SYSRESET*. A SYSRESET* may be generated by the following:
❏ RESET switch
❏ Power up reset
❏ Watchdog timeout
❏ Control bit in the LCSR
SYSRESET* remains asserted for at least 200 msec, as required by
the VMEbus specification.
Similarly, the VMEchip2 provides an input signal and a control bit
to initiate a local reset operation. By setting a control bit, software
can maintain a board in a reset state, disabling a faulty board from
participating in normal system operation. The local reset driver is
enabled even when the VMEchip2 is not the system controller. A
local reset may be generated by:
❏ RESET switch
❏ Power up reset
❏ Watchdog timeout
❏ VMEbus SYSRESET*
❏ Control bit in the GCSR