BENTLY 146031-01 3500/22M框架接口模塊
多路開關。使用MVME712M模塊時，黃色當LAN通電時，MVME712M前面板上的LED（DS1）亮起可用，表明多路開關良好。MVME177通過二極管提供SCSI終端電源以及位于P2適配器板上的1安培多功能開關F1。如果多開關熔斷（即打開），SCSI設備可能無法運行或者可能功能不穩(wěn)定。使用P2適配器板時通過MVME712M和SCSI總線連接到MVME712M，MVME712M前面板上的綠色LED（DS2）有SCSI終端電源時亮起。
BENTLY 146031-01 3500/22M框架接口模塊如果LED閃爍在SCSI總線操作期間，應檢查多路開關。中止開關S1當通過軟件啟用時，嵌入式前面板中止開關在用戶可編程級別生成中斷。通常情況下用于中止程序執(zhí)行并返回177Bug調(diào)試器固件位于MVME177 EPROM中。VMEchip2中的中止開關中斷器是一個連接到中止開關的邊緣敏感斷續(xù)器。這對斷續(xù)器進行過濾，以消除開關反彈。復位開關S2嵌入式前面板重置開關重置所有車載設備，如果板是系統(tǒng)控制器，則驅(qū)動SYSRESET*。重置開關可能被軟件禁用。VMEchip2包括全局和本地重置驅(qū)動程序。什么時候該芯片作為VMEbus系統(tǒng)控制器、復位驅(qū)動器運行通過斷言VMEbus信號提供全局系統(tǒng)重置系統(tǒng)重置*。系統(tǒng)重置*可由以下方式生成：? 復位開關? 通電復位? 看門狗超時? LCSR中的控制位SYSRESET*保持斷言狀態(tài)至少200毫秒，如VMEbus規(guī)范。類似地，VMEchip2提供輸入信號和控制位本地重置操作。通過設置控制位，軟件可以將電路板保持在重置狀態(tài)，從而禁用故障電路板系統(tǒng)正常運行。本地重置驅(qū)動程序為即使VMEchip2不是系統(tǒng)控制器也啟用。A.
本地重置可通過以下方式生成：? 復位開關? 通電復位? 看門狗超時? VMEbus系統(tǒng)重置*? GCSR中的控制位
the polyswitch. When using the MVME712M module, the yellow
LED (DS1) on the MVME712M front panel lights when LAN power
is available, indicating that the polyswitch is good.
The MVME177 provides SCSI terminator power through a diode
and a 1 amp polyswitch F1 located on the P2 Adapter Board. If the
polyswitch is blown (i.e., open), the SCSI devices may not operate
or may function erratically. When the P2 Adapter Board is used
with an MVME712M and the SCSI bus is connected to the
MVME712M, the green LED (DS2) on the MVME712M front panel
lights when there is SCSI terminator power. If the LED flickers
during SCSI bus operation, the polyswitch should be checked.ABORT Switch S1
When enabled by software, the recessed front panel ABORT switch
generates an interrupt at a user-programmable level. It is normally
used to abort program execution and return to the 177Bug
debugger firmware located in the MVME177 EPROMs.
The ABORT switch interrupter in the VMEchip2 is an
edge-sensitive interrupter connected to the ABORT switch. This
interrupter is filtered to remove switch bounce. RESET Switch S2
The recessed front panel RESET switch resets all onboard devices,
and drives SYSRESET* if the board is system controller. The RESET
switch may be disabled by software.
The VMEchip2 includes both a global and a local reset driver. When
the chip operates as the VMEbus system controller, the reset driver
provides a global system reset by asserting the VMEbus signal
SYSRESET*. A SYSRESET* may be generated by the following:
? RESET switch
? Power up reset
? Watchdog timeout
? Control bit in the LCSR
SYSRESET* remains asserted for at least 200 msec, as required by
the VMEbus specification.
Similarly, the VMEchip2 provides an input signal and a control bit
to initiate a local reset operation. By setting a control bit, software
can maintain a board in a reset state, disabling a faulty board from
participating in normal system operation. The local reset driver is
enabled even when the VMEchip2 is not the system controller. A
local reset may be generated by:
? RESET switch
? Power up reset
? Watchdog timeout
? VMEbus SYSRESET*
? Control bit in the GCSR
