CI687K01 3BSE043660R1处理控制模块,ABB说明书

MC2chip和可选控制器中都提供了看门狗定时器VMEchip2。计时器独立但并行运行。当如果启用了看门狗定时器，则必须在编程时间，否则将超时。看门狗计时器可能是编程生成系统复位信号、本地复位信号或电路板如果超时，则发出故障信号。请参阅中的VMEchip2和MC2chipMVME172 VME嵌入式控制器程序员参考指南有关详细的编程信息。

CI687K01 3BSE043660R1处理控制模块看门狗定时器逻辑在VMEchip2和MC2chip中重复亚瑟士。因为VMEchip2中的看门狗定时器功能是MC2chip（系统重置功能）中该功能的超集，定时器在VMEchip2中，除MVME172LX不包括VMEbus接口（“否VMEbus接口”选项）。软件可编程硬件中断8个软件可编程硬件中断由VMEchip2。这些中断允许软件创建硬件中断。请参阅MVME172 VME嵌入式控制器中的VMEchip2详细编程信息的程序员参考指南。本地总线超时MVME172LX在VMEchip2和本地总线的MC2chip。当定时器启用且本地总线访问超时，传输错误确认（TEA）信号发送到本地总线主机。超时值可由软件选择8µs，64微秒、256微秒或无限。本地总线计时器在VMEbus绑定循环。VMEbus绑定周期由VMEbus计时访问计时器和VMEbus全局计时器。请参阅VMEchip2和MVME172 VME嵌入式控制器程序员的MC2chip有关详细编程信息的参考指南。MC2chip还为MVME172LX提供本地总线超时逻辑没有可选的VMEbus接口（即没有VMEchip2）。访问计时器逻辑在VMEchip2和MC2chip中重复亚瑟士。因为VMEchip2中的本地总线计时器可以检测到非车载访问和MC2chip本地总线计时器不能，计时器在除MVME172LX版本外，所有情况下均使用VMEchip2

不包括VMEbus接口（“无VMEbus接口选项”）。

A watchdog timer is provided in both the MC2chip and the optional

VMEchip2. The timers operate independently but in parallel. When the

watchdog timers are enabled, they must be reset by software within the

programmed time or they will time out. The watchdog timers may be

programmed to generate a SYSRESET signal, local reset signal, or board

fail signal if they time out. Refer to the VMEchip2 and the MC2chip in the

MVME172 VME Embedded Controller Programmer’s Reference Guide

for detailed programming information.

The watchdog timer logic is duplicated in the VMEchip2 and MC2chip

ASICs. Because the watchdog timer function in the VMEchip2 is a

superset of that function in the MC2chip (system reset function), the timer

in the VMEchip2 is used in all cases except for the version of the

MVME172LX 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.

Refer to the VMEchip2 in the MVME172 VME Embedded Controller

Programmer’s Reference Guide for detailed programming information.

Local Bus Timeout

The MVME172LX provides timeout functions 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 selectable by software for 8 µsec, 64

µsec, 256 µsec, or infinite. 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 in the MVME172 VME Embedded Controller Programmer’s

Reference Guide for detailed programming information.

The MC2chip also provides local bus timeout logic for MVME172LXs

without the optional VMEbus interface (i.e., without the VMEchip2).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 MVME172LX

which does not include the VMEbus interface ("No VMEbus Interface

option").