Motorola MVME2400 Series Instrukcja Obsługi Pobierz pdf (Strona 43)

MVME240x

http://www.mcg.mot.com/literature 2-3

ABT (S1)

When activated by software, the Abort switch,

ABT, can generate an

interrupt signal from the base board to the processor at a user-

programmable level. The interrupt is normally used to abort program

execution and return control to the debugger firmware located in the

MVME240x Flash memory. The interrupt signal reaches the processor

module via ISA bus interrupt line IRQ8

∗. The signal is also available from

the general purpose I/O port, which allows software to poll the Abort switch after

an IRQ8* interrupt and verify that it has been pressed.

The interrupter connected to the

ABT switch is an edge-sensitive circuit,

filtered to remove switch bounce.

RST (S2)

The Reset switch,

RST, resets all onboard devices and causes HRESET* to

be asserted in the MPC603 or MPC604. It also drives a

SYSRESET*

signal if the MVME240x VME processor module is the system controller.

The Universe ASIC includes both a global and a local reset driver. When

the Universe operates as the VMEbus system controller, the reset driver

provides a global system reset by asserting the VMEbus signal

SYSRESET*. A SYSRESET* signal may be generated by the RESET

switch, a power-up reset, a watchdog timeout, or by a control bit in the

Miscellaneous Control Register (MISC_CTL) in the Universe ASIC.

SYSRESET* remains asserted for at least 200 ms, as required by the

VMEbus specification.

Similarly, the Universe ASIC supplies 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 Universe ASIC is not system controller. Local resets may be generated

by the

RST switch, a power-up reset, a watchdog timeout, a VMEbus

SYSRESET*, or a control bit in the MISC_CTL register.

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Motorola MVME2400 Series Instrukcja Obsługi Strona 43