Software-Programmable Hardware Interrupts; Local Bus Timeout - Motorola 700 Series Installation And Use Manual

Block Diagram
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Software-Programmable Hardware Interrupts

Eight software-programmable hardware interrupts are provided
by the VMEchip2. These interrupts allow software to create a
hardware interrupt. Refer to the VMEchip2 description in the
MVME162LX Embedded Controller Programmer's Reference Guide for
detailed programming information.

Local Bus Timeout

The MVME162LX provides a timeout function in the VMEchip2
and the MC2chip for the local bus. When the timer is enabled and a
local bus access times out, a Transfer Error Acknowledge (TEA)
signal is sent to the local bus master. The timeout value is software-
selectable for 8 µsec, 64 µsec, 256 µsec, or infinity. The local bus
timer does not operate during VMEbus bound cycles. VMEbus
bound cycles are timed by the VMEbus access timer and the
VMEbus global timer. Refer to the VMEchip2 and the MC2chip
descriptions in the MVME162LX Embedded Controller Programmer's
Reference Guide for detailed programming information.
The MC2chip also provides local bus timeout logic for
MVME162LXs without the optional VMEbus interface (i.e., without
the VMEchip2 ASIC).
The access timer logic is duplicated in the VMEchip2 and MC2chip
ASICs. Because the local bus timer in the VMEchip2 can detect an
offboard access and the MC2chip local bus timer cannot, the timer
in the VMEchip2 is used in all cases except for the version of the
MVME162LX which does not include the VMEbus interface
(described under ''No-VMEbus-Interface option").
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