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Functional Description
Local Resources
The MVME162 includes many resources for the local processor. These include
tick timers, software-programmable hardware interrupts, watchdog timer,
and local bus timeout.
Programmable Tick Timers
Six 32-bit programmable tick timers with 1 µs resolution are provided, two in
the VMEchip2 and four in the MCchip. The tick timers can be programmed to
generate periodic interrupts to the processor. Refer to the VMEchip2 and
MCchip in the MVME162 Embedded Controller Programmer’s Reference Guide for
detailed programming information.
Watchdog Timer
A watchdog timer function is provided in the VMEchip2 and the MCchip.
When the watchdog timer is enabled, it must be reset by software within the
programmed time or it times out. The watchdog timer can be programmed to
generate a SYSRESET signal, local reset signal, or board fail signal if it times
out. Refer to the VMEchip2 and the MCchip in the MVME162 Embedded
Controller Programmer’s Reference Guide for detailed programming information.
The watchdog timer logic is duplicated in the VMEchip2 and MCchip ASICs.
Because the watchdog timer function in the VMEchip2 is a superset of that
function in the MCchip (system reset function), the timer in the VMEchip2 is
used in all cases except for the version of the MVME162 which does not
include the VMEbus interface ("No VMEbus Interface" option).
Software-Programmable Hardware Interrupts
Eight software-programmable hardware interrupts are provided by the
VMEchip2. These interrupts allow software to create a hardware interrupt.
Local Bus Timeout
The MVME162 provides a timeout function in the VMEchip2 and the MCchip
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 selectable by software 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.
MVME162IG/D2
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