DEIF SCM4.1負(fù)載單元控制器，SCM4.1使用配置教程
實用程序中斷向量寄存器提供本地每個實用程序都具有唯一向量的CPU中斷。仔細(xì)檢查后發(fā)現(xiàn)每個公用電中斷的級別，如本章中的實用程序中斷掩碼寄存器部分是與分配的ID相同。這由反映地址行A01-A03的狀態(tài)，即當(dāng)本地CPU確認(rèn)中斷到效用向量寄存器的位0-2。在正常運行過程中訪問該寄存器時CPU讀取周期，位0-2產(chǎn)生寄存器偏移值（即%xxxxx 001）。
DEIF SCM4.1負(fù)載單元控制器實用程序中斷向量寄存器的內(nèi)容當(dāng)一個公用設(shè)施中斷時，不得更改處于活動狀態(tài)。實用程序中斷向量寄存器的下三位是由VMEchip編碼，以唯一標(biāo)識導(dǎo)致公用事業(yè)中斷請求，如表4-7所示。位3-7 UVB3到UVB7是效用向量基位。寄存器的上五位可通過以下方式編程：軟件為中提供的矢量提供唯一的基礎(chǔ)確認(rèn)公用電中斷之一的過程。這些位通過任何重置清除。該寄存器用于配置中斷請求中斷器激活以請求中斷VMEbus。三條中斷電平選擇線的編碼如所示表4-8。將非0值寫入這三個位會導(dǎo)致用于激活相應(yīng)VMEbus IRQ線路的斷路器。由于中斷器在確認(rèn)釋放（ROAK）模式下工作，因此中斷請求寄存器為清除，當(dāng)芯片響應(yīng)VMEbus中斷確認(rèn)周期。這些位通過系統(tǒng)重置。
The utility interrupt vector register provides the local
CPU with a unique vector for each of the utility
interrupts. Close examination reveals that the assigned
level of each of the utility interrupts, as defined in the
Utility Interrupt Mask Register section in this chapter, is
the same as its assigned ID. This is implemented by
reflecting the state of the address lines A01-A03, that
the local CPU drives when it acknowledges an
interrupt, onto bits 0-2 of the utility vector register.
When accessing this register in the course of a normal
CPU read cycle, bit 0-2 yields the register offset value
(which is %xxxxx001).
The contents of the utility interrupt vector register
must not be changed while one of the utility interrupts
is active. The lower three bits of the utility interrupt vector register are
encoded by the VMEchip to uniquely identify the function that
caused the utility interrupt request as shown in Table 4-7.
Bits 3-7 UVB3 through UVB7 are utility vector base bits.
The upper five bits of the register are programmable by
software to provide a unique base for the vector provided in the
course of acknowledging one of the utility interrupts. These bits
are cleared by any reset. This register is used to configure the interrupt request
line that the interrupter activates to request an
interrupt on the VMEbus.
The three interrupt level select lines are encoded as shown in
Table 4-8. Writing a non-0 value to these three bits causes the
interrupter to activate the corresponding VMEbus IRQ line.
Because the interrupter operates in the Release-OnAcknowledge (ROAK) mode, the interrupt request register is
cleared, deactivating the IRQ line when the chip responds to a
VMEbus interrupt acknowledge cycle. These bits are cleared by
SYSRESET.
