Technical data

2
MVME51005E Single Board Computer Installation and Use (6806800A38B)
13
2 Operation
Introduction
This chapter provides operating instructions for the MVME5100 Single Board Computer. It
includes necessary information about powering up the system along with the functionality of the
switches, status indicators and I/O ports on the front panels of the board.
Switches and Indicators
The front panel of the MVME5100, as shown in Figure 1-1, incorporates one dual function
toggle switch
(ABT/RST) and two Light-Emitting Diode (LED) status indicators (BFL, CPU)
located on the front panel.
ABT/RST Switch
The ABT/RST switch operates in the following manner: if pressed for less than 5 seconds, the
ABORT function is selected, if pressed for more than 5 seconds, the RESET function is selected.
Each function is described below.
Abort Function
When toggled to ABT, the switch generates an interrupt signal to the processor. The interrupt is
normally used to abort program execution and return control to the debugger firmware located
in the processor and flash memory.
The interrupt signal reaches the processor via ISA bus interrupt line IRQ8. The interrupter
connected to the
ABORT switch is an edge-sensitive circuit, filtered to remove switch bounce.
Reset Function
When toggled to RST, the switch resets all onboard devices. To generate a reset, the switch
must be depressed for more than five seconds.
The on-board Universe ASIC includes both a global and a local reset driver. When the ASIC
operates as the System Controller, the reset driver provides a global system reset by asserting
the SYSRESET# signal.
Additionaly, when the MVME5100 is configured as a System Controller (SCON), a
SYSRESET# signal may be generated by toggling the
ABT/RST switch to RST, or by a power-
up reset, or by a watchdog timeout, or by a control bit in the Miscellaneous Control Register
(MISC_CTL) in the Universe ASIC.