FBM223模拟量输出模块,FOXBORO说明书在线阅读
自动按指定顺序扫描控制器和设备，直到找到包含引导媒体的有效可引导设备或列表已用尽。
如果找到有效的可引导设备，则启动该设备的引导。这个控制器扫描顺序从最低的控制器逻辑单元开始检测到的数量（LUN）为检测到的最高LUN。（参考附录C对于默认LUN）。
通电时，启用网络引导，并提供驱动器和控制器遇到的数字有效，将在系统控制台：“正在进行网络引导…要中止hit<BREAK>”在该消息之后，
FBM223模拟量输出模块当调试固件等待各种控制器和驱动器达到速度然后开始实际的输入/输出：程序指向指定媒体的卷ID加载到RAM中，并将控制传递给它。
但是，如果在此期间您希望在不启动网络的情况下获得控制权，您可以按<BREAK>键或软件中止或重置开关。网络自动引导由NIOT和ENV命令。这些参数允许选择特定的引导设备，并允许对引导延迟进行编程。参考ENV有关更多详细信息，请参阅附录A中的命令。
重新启动系统用户可以通过三种不同的方式将系统初始化为已知状态：重置、中止和中断。每一个都有其特点，使其更在某些情况下比其他人更合适。
调试器在重置条件下具有特殊功能。此功能是通过同时按下重置和中止开关激活。此功能指示调试器使用默认设置/操作ROM中的参数与NVRAM中用户的设置/操作参数。
如果用户的设置/操作参数已损坏或不符合健全性检查。请参阅ENV命令（附录A）适用于ROM默认值。重置按下并释放MVME197LE前面板重置开关启动系统重置。冷复位和热复位模式可用，并由使用重置命令。默认情况下，197Bug处于冷模式。在期间冷复位时，将进行整个系统初始化，就像MVME197LE刚刚通电一样。所有静态变量（包括磁盘设备和控制器参数）恢复到其默认状态。断点表和偏移量寄存器被清除。目标寄存器无效。输入和输出字符队列已清除。车载设备（计时器、串行端口等）包括重置，前两个串行端口重新配置为其默认状态。
在热复位过程中，197Bug变量和表格被保留，以及目标状态寄存器和断点。
如果处理器曾经停止，或者如果197Bug环境曾经丢失（向量表被破坏、堆栈损坏等）。
automatically scans for controllers and devices in a specified sequence until a
valid bootable device containing a boot media is found or the list is exhausted.
If a valid bootable device is found, a boot from that device is started. The
controller scanning sequence goes from the lowest controller Logical Unit
Number (LUN) detected to the highest LUN detected. (Refer to Appendix C
for default LUNs).
At power-up, Network Boot is enabled, and providing the drive and controller
numbers encountered are valid, the following message is displayed upon the
system console:
“Network Boot in progress... To abort hit <BREAK>”
Following this message there is approximately a thirty-second delay while the
debug firmware waits for the various controllers and drives to come up to
speed. Then the actual I/O is begun: the program pointed to within the
volume ID of the media specified is loaded into RAM and control passed to it.
If, however, during this time you want to gain control without Network Boot,
you can press the <BREAK> key or the software ABORT or RESET switches.
Network Auto Boot is controlled by parameters contained in the NIOT and
ENV commands. These parameters allow the selection of specific boot devices,
systems, and files, and allow programming of the Boot delay. Refer to the ENV
command in Appendix A for more details.
Restarting the System
The user can initialize the system to a known state in three different ways:
reset, abort, and break. Each has characteristics which make it more
appropriate than the others in certain situations.
The debugger has a special feature upon a reset condition. This feature is
activated by depressing the RESET and ABORT switches at the same time.
This feature instructs the debugger to use the default setup/operation
parameters in ROM versus the user’s setup/operation parameters in NVRAM.
This feature can be used in the event the user’s setup/operation parameters
are corrupted or do not meet a sanity check. Refer to the ENV command
(Appendix A) for the ROM defaults.
Reset
Pressing and releasing the MVME197LE front panel RESET switch initiates a
system reset. COLD and WARM reset modes are available and are selected by
using the RESET command. By default, 197Bug is in COLD mode. During
COLD reset, a total system initialization takes place, as if the MVME197LE had just been powered up. All static variables (including disk device and controller
parameters) are restored to their default states. The breakpoint table and offset
registers are cleared. The target registers are invalidated. Input and output
character queues are cleared. Onboard devices (timer, serial ports, etc.) are
reset, and the first two serial ports are reconfigured to their default state.
During WARM reset, the 197Bug variables and tables are preserved, as well as
the target state registers and breakpoints.
Reset must be used if the processor ever halts, or if the 197Bug environment is
ever lost (vector table is destroyed, stack corrupted, etc.).
