Software Initialization
3-9
3
❏
Pressing the front panel RESET switch (if the system
controller function is disabled)
❏
Asserting a bit in the board control register in the GCSR
❏
SYSRESET*
❏
Power-up reset
Note
The GCSR allows a VMEbus master to reset the local
bus. This feature is very dangerous and should be used
with caution. The local reset feature is a partial system
reset, not a complete system reset such as power-up
reset or SYSRESET*. When the local bus reset signal is
asserted, a local bus cycle may be aborted. The
VMEchip2 is connected to both the local bus and the
VMEbus and if the aborted cycle is bound for the
VMEbus, erratic operation may result.
Communications between the local processor and a
VMEbus master should use interrupts or mailbox
locations; reset should not be used in normal
communications. Reset should be used only when the
local processor is halted or the local bus is hung and
reset is the last resort.
Any VMEbus access to the MVME177 while it is in the reset state is
ignored. If a global bus timer is enabled, a bus error is generated.
Summary of Contents for MVME177
Page 1: ...MVME177 Single Board Computer Installation and Use Manual VME177A IH2 ...
Page 6: ......
Page 42: ...Hardware Preparation and Installation 2 18 2 ...
Page 52: ...Operating Instructions 3 10 3 ...
Page 80: ...EIA 232 D Interconnections A 8 A ...