Motorola MVME177P, Installation And Use Manual

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Functional Description
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Programmable Tick Timers
Four 32-bit programmable tick timers with 1
µ
s resolution are available:
two in the VMEchip2 ASIC and two in the PCCchip2 ASIC. The tick
timers may be programmed to generate periodic interrupts to the
processor. Refer to the VMEchip2 and PCCchip2 descriptions in the
Programmer’s Reference Guide for detailed programming information.
Watchdog Timer
A watchdog timer function is provided in the VMEchip2 ASIC. When the
watchdog timer is enabled, it must be reset by software within the
programmed interval or it times out. The watchdog timer can be
programmed to generate a SYSRESET signal, a local reset signal, or a
board fail signal if it times out. Refer to the VMEchip2 description in the
Programmer’s Reference Guide for detailed programming information.
Software-Programmable Hardware Interrupts
The VMEchip2 ASIC supplies eight software-programmable hardware
interrupts. These interrupts allow software to create a hardware interrupt.
Refer to the VMEchip2 description in the Programmer’s Reference Guide
for detailed programming information.
Local Bus Timeout
The MVME177P provides a timeout function in the VMEchip2 ASIC 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
µ
sec, 64
µ
sec, 256
µ
sec,
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 description in the
Programmer’s Reference Guide for detailed programming information.