P0917HD输入输出模块,FOXBORO实验数据
通过按下并释放上的Abort开关来调用AbortMVME197LE前面板。每当执行用户时调用abort时程序（运行目标代码），捕获处理器状态的“快照”并存储在目标寄存器中。（在调试器中工作时，中止仅捕获和存储指令指针（IP）、状态寄存器和格式/矢量信息）。因此，在以下情况下中止最合适：终止正在调试的用户程序。中止应用于如果程序陷入循环等，则重新获得控制。目标IP，寄存器内容等有助于查明故障。
P0917HD输入输出模块按下并释放中止开关会产生局部电路板条件如果启用，可能会中断处理器。目标寄存器，反映按下中止开关时的机器状态显示在屏幕。用户代码中安装的任何断点都将被删除，并且断点表保持不变。控件返回给调试器。打破按下并释放按钮上的“Break”（断开）键可生成“Break”（断开）终端键盘。中断不会生成中断。唯一的时差在控制台端口发送或接收字符时识别。打破删除用户代码中的任何断点，并保留断点表完整的如果函数为使用系统调用输入。然后，用户可以通过以下方式访问此机器状态：诊断目的。许多情况下，需要在调试之前终止调试器命令例如，完成一大块内存的显示。中断允许用户终止命令。SYSFAIL*断言/否定在重置/通电条件下，调试器断言VMEbus SYSFAIL*线路（参考VMEbus规范）。如果任何发生了以下情况：❏ 置信度测试失败❏ NVRAM校验和错误
❏ NVRAM电池电量低❏ 本地内存配置状态❏ 自检（如果系统模式）已完成，但出现错误
❏ MPU时钟速度计算失败调试器初始化完成后，上述任何情况均未发生发生时，SYSFAIL*行被取反。这向用户或VMEbus指示掌握调试器的状态。在多计算机配置中，其他VMEbus主机可以查看相关的控制和状态寄存器确定哪个CPU正在断言SYSFAIL*。SYSFAIL*断言/否定为也受ENV命令的影响。参考附录A。MPU时钟速度计算计算微处理器的时钟速度，并对照用户进行检查NVRAM中包含的可定义参数（请参阅ENV命令）。如果检查失败，将显示警告消息。计算的时钟速度也是对照已知的时钟速度和公差进行检查。
Abort is invoked by pressing and releasing the ABORT switch on the
MVME197LE front panel. Whenever abort is invoked when executing a user
program (running target code), a “snapshot” of the processor state is captured
and stored in the target registers. (When working in the debugger, abort
captures and stores only the Instruction Pointer (IP), status register, and
format/vector information). For this reason, abort is most appropriate when
terminating a user program that is being debugged. Abort should be used to
regain control if the program gets caught in a loop, etc. The target IP, register
contents, etc., help to pinpoint the malfunction.
Pressing and releasing the ABORT switch generates a local board condition
which may interrupt the processor if enabled. The target registers, reflecting
the machine state at the time the ABORT switch was pressed, are displayed on
the screen. Any breakpoints installed in the user code are removed and the
breakpoint table remains intact. Control is returned to the debugger.
Break
A “Break” is generated by pressing and releasing the BREAK key on the
terminal keyboard. Break does not generate an interrupt. The only time break
is recognized is when characters are sent or received by the console port. Break
removes any breakpoints in the user code and keeps the breakpoint table
intact. Break also takes a snapshot of the machine state if the function was
entered using SYSCALL. This machine state is then accessible to the user for
diagnostic purposes.
Many times it is desired to terminate a debugger command prior to its
completion, for example, the display of a large block of memory. Break allows
the user to terminate the command.SYSFAIL* Assertion/Negation
Upon a reset/power up condition the debugger asserts the VMEbus SYSFAIL*
line (refer to the VMEbus specification). SYSFAIL* stays asserted if any of the
following has occurred:
❏ confidence test failure
❏ NVRAM checksum error
❏ NVRAM low battery condition
❏ local memory configuration status
❏ self test (if system mode) has completed with error
❏ MPU clock speed calculation failure
After debugger initialization is done and any of the above situations has not
occurred, the SYSFAIL* line is negated. This indicates to the user or VMEbus
masters the state of the debugger. In a multi-computer configuration, other
VMEbus masters could view the pertinent control and status registers to
determine which CPU is asserting SYSFAIL*. SYSFAIL* assertion/negation is
also affected by the ENV command. Refer to Appendix A.
MPU Clock Speed Calculation
The clock speed of the microprocessor is calculated and checked against a user
definable parameter housed in NVRAM (refer to the ENV command). If the
check fails, a warning message is displayed. The calculated clock speed is also
checked against known clock speeds and tolerances.
